Global network Internet. Presentation on the topic: "Global network" Global computer networks Internet presentation
Read also
Computer network is a set of computers connected by information transmission lines.
The exchange of information over a computer network is called telecommunications.
Types of computer networks
Local
networks
Global network INTERNET
Regional networks
Corporate networks
The local area network is small. computer network operating within the same premises, one enterprise.
Network topologies
1. Bus topology
All computers are connected to one cable (bus). Terminators are installed at the ends of the cable. The cable used is a coaxial cable. Disabling any of the connected devices does not affect network operation.
2. Star topology
Each computer is connected by a separate wire to a separate port of the hub (Hub) or switch (Switches).
3. Ring topology
In a ring topology, computers are connected to a cable that is closed in a ring. Unlike the passive "bus" topology, here each computer amplifies the signals and passes them on to the next computer. Therefore, if one computer fails, the functioning of the network may be disrupted.
Corporate networks - formed to combine computers of certain organizations (military, banking, etc.) that are interested in protecting information from unauthorized access.
A corporate network can unite thousands and tens of thousands of computers located in different cities and countries.
An example is the Microsoft network - MicroSoft Network (MSN)
Regional networks - unite computers within the same region (city, country, continent).
The need for the formation of a single world information space led to the creation of the GLOBAL COMPUTER NETWORK INTERNET.
The need for the formation of a single global information space led to the creation
GLOBAL COMPUTER NETWORK INTERNET.
Regional computer networks, united
to the global Internet
Regional computer networks connected to the global Internet
The reliability of the network is ensured big amount channels of information transmission with high bandwidth between local, regional and corporate networks.
Internet – is a global computer network in which local, regional and corporate networks interconnected by numerous channels of information transmission with high bandwidth
Currently (January 2008), the backbone of the Internet is over 400 million servers.
Connection and internet
Each local, regional or corporate network has at least one computer (Internet server) that has a permanent connection to the Internet.
1. Optical fiber communication lines
However, in cases where inconveniently located or remote computer networks are connected, when cable laying is difficult or impossible,
2. Wireless communication lines
If the transmitting and receiving antennas are within line of sight, then
3. Radio channels
otherwise, the exchange of information takes place via
4. satellite channel using special antennas
Hundreds of millions of user computers may periodically connect to the Internet using ISPs. Such a connection can be made both via fiber optic lines and switched telephone channels. Internet providers have high-speed connections of their servers to the Internet and therefore can provide Internet access via telephone channels to hundreds and thousands of users simultaneously.
To connect the user's computer via a telephone channel to the server of the Internet provider, modems must be connected to both computers. Modems provide transmission of digital computer data via analog telephone channels at speeds up to 56 Kbps.
An example of a regular modem
Modern ADSL technologies make it possible to use ordinary telephone channels for high-speed (1 Mbit/s and higher) Internet connection. It is important that while phone number remains free.
Regular and ADSL modems connect to the computer's USB port and to the telephone jack.
ADSL modem example
Laptop users can connect to the Internet using wireless technology WiFi. Access points are installed at railway stations, airports and other public places wireless communication connected to the Internet. Within a radius of 100 meters laptop equipped with wireless network card, automatically accesses the Internet at speeds up to 54 Mbps.
PLC is a new telecommunications technology based on the use of power networks for high-speed information exchange (Internet from a socket). In this technology based on frequency division of a signal, a high-speed data stream is divided into several low-speed ones, each of which is transmitted on a separate frequency, and then they are combined into one signal.
At the same time, Internet devices can "see" and decode information, although conventional electrical devices- incandescent lamps, engines, etc. - do not even "guess" the presence of signals network traffic and work normally.
Addressing in the Internet
IP address
In order for computers to be able to find each other in the process of exchanging information, there is a one system addressing based on usage IP addresses.
According to Hartley's formula N=2 I , Where N is the number of possible information messages, and I- the amount of information that the received message carries,
The IP address carries the amount of information I = 32 bits, therefore the total number of possible IP addresses N is:
N=2 I = 2 32 = 4 294 967 296
So, an IP address with a length of 32 bits allows you to connect more than 4 billion computers to the Internet.
Every computer connected to the Internet has its own unique 32-bit binary IP address.
IP address example: 213.171.37.202
For readability, a binary 32-bit IP address is divided into
4 parts of 8 bits each and each part can be represented in both binary and decimal form.
In decimal notation, an IP address consists of 4 numbers separated by dots, each of which ranges from 0 to 255.
The IP addressing system takes into account the structure of the Internet, i.e. that the Internet is a network of networks, not a collection of individual computers. An IP address contains the network address and the address of a computer on that network.
Binary
Decimal
For maximum flexibility in the distribution process
IP addresses, depending on the number of computers on the network, the addresses are divided into 3 classes A, B, C. The first bits are allocated to identify the class, and the rest are divided into the network address and the computer address.
For example, a class A network address has only 7 bits for the network address and 24 bits for the computer address, i.e. can only exist N=2 I = 2 7 = 128 networks of this class, but each of which may contain N=2 I = 2 24 = 16 777 216 computers
Binary
Decimal
Class A
Class B
Network address (7bit)
Class C
Network address (14bit)
Computer address (24 bits)
Network address (21bit)
Computer address (16 bits)
Computer address (8bit)
Binary
Decimal
Class A
Class B
Class C
Network address (7bit)
Network address (14bit)
Computer address (24 bits)
Network address (21bit)
Computer address (16 bits)
Network address (8bit)
The belonging of a computer to a network of one class or another is easily determined by the first number of the computer's IP address:
- class A addresses - a number from 0 to 127;
- class B addresses - a number from 128 to 191;
- class C addresses - a number from 192 to 223;
Question: What type of network does our IP address belong to?
Domain name system
Computers can easily find each other by numerical IP address, however, it is not easy for a person to remember a numerical address, and for the convenience of Internet users, Domain Name System (DNS - Domain Name System).
Domain names and IP addresses are distributed by an international clearing house (ICANN).
DNS consists of several words separated by dots. The structure of the name reflects the hierarchical structure DNS . The domains of the first ( top level), to the left - second-level domains, etc.
Example: herba.msu.ru
this address belongs to the herba computer, which is registered in the msu (Moscow State University) level 2 domain in Russia (ru)/
The Domain Name System maps a computer's numeric IP address to a unique domain name.
Name (host) of the computer
Top-level domains are of 2 types:
- Geographic (two-letter - each country has a two-letter code);
- Administrative (three-letter)
2nd level domains are registered by 1st level domain administrators. So Microsoft registered the Microsoft 2-level domain in the administrative top-level domain com. (Microsoft's main server is named www.microsoft.com)
Administrative
Organization type
a commercial
Geographic
A country
educational
US government
International
Germany
US military
Computer network
former USSR
non-profit
England/Ireland
When during business communication representatives of two firms exchange business cards, then they (business cards) will necessarily contain the e-mail address and the name of the company's corporate Web site. At the same time, you can also hear how the interlocutors exchange "Internet addresses" ("electronic addresses") of companies. In all of the above cases, one way or another we are talking on the use of domain names.
In an e-mail address, formally, the domain name can be considered what is written after the symbol - "@". For example, in [email protected] the domain name of the mail host is corp.ru.
Attention: by the name itself, no access to the resource can be obtained.
The procedure for using the name is as follows:
1. first by name in hosts file find an IP address
2. then a connection is established with the remote information resource using the IP address.
Thanks to the domain name system, not only every computer, but also every file on the Internet has its own exact unique address - URL (Universal Resource Locator - “Universal Resource Locator”). It is built like this:
protocol:// domain name of the computer/ address in the directory tree on the computer/file name
The Internet, which is a network of networks and unites a huge number of different local, regional and corporate networks, functions and develops through the use of single principle routing and transport of data.
Routing and transport of data on the Internet is based on
TCP / IP protocol, which is the basic "law" of the Internet.
The term TCP/IP includes the names of two data transfer protocols:
- TCP (Transmission Control Protocol) - transport protocol;
- IP (Internet Protocol) - routing protocol
Internet Protocol (IP) provides routing of IP packets, i.e. delivery of information from the sender's computer to the recipient's computer.
sender
Transmission Control Protocol (TCP), those. transport protocol, provides splitting of files into IP packets in the process of transmission and assembly of files in the process of receiving
sender. For example: "To: 198.78.213.185", "From: 193.124.5.33". The content of such an "envelope" with information is called Internet package (IP package) and is a set of bytes. IP packets, on the way to the recipient computer, pass through numerous intermediate Internet servers, on which the routing operation takes place (determining their further path)
DATA ROUTING
In order for the letter to reach its destination, the address of the recipient and the address of the sender are indicated on the envelope. Similarly, information is transferred between network computers. Where the IP addresses of the computers of the recipient and
sender
Routing Internet packages (IP packets ) ensures the delivery of information from the sending computer to the receiving computer.
Internet packet delivery routes can be completely different, and therefore Internet packets sent first may reach the recipient computer last.
For example:
recipient
sender
The speed of information transfer on the Internet does not depend on the remoteness of the server
The speed of information transfer on the Internet does not depend on the remoteness of the Internet server, but on the route of the information, i.e. on the number of intermediate servers and the quality of communication lines (their bandwidth), through which information is transmitted from server to server
DATA TRANSPORT
Computers often exchange large files. If such a file is sent in its entirety, then it can “clog” this communication channel, i.e. make it unavailable for forwarding other messages.
To prevent this from happening, on the sender's computer, you need to break big file into small parts, number them and transform them into separate Internet packages to the recipient computer.
On the receiving computer, you need to collect original file from the individual parts in the correct order, so the file can only be assembled when all Internet packets have arrived.
Data transport is done by splitting the files into Internet packets on the sending computer, routing each packet individually, and reassembling the files from the packets in their original order on the receiving computer.
For example:
recipient
Description of the presentation on individual slides:
1 slide
Description of the slide:
2 slide
Description of the slide:
Internet history. The Internet is the World Wide Web, a global information space. The history of the emergence and development of this world wide web is bright and unusual, because already 10 years after its appearance, it has conquered many organizations and countries that began to actively use the network for work. At first, the Internet served exclusively for groups of researchers and scientists, soon the military squeezed into this group, and after that, businessmen. After that, the popularity of the Internet grew rapidly. Users were seduced by the speed of information transfer, cheap global communication, many easy and affordable programs, a unique database, and so on. Today, at a low cost of services, each user can access information services from all countries of the world. Also, the Internet today provides opportunities for global communication around the world. Naturally, this is convenient for firms that have branches in different points the globe, for transnational corporations, as well as for management structures.
3 slide
Description of the slide:
How and when did the Internet appear. It happened over 50 years ago. Back in 1961, on the instructions of the US Department of Defense. began work on a pilot project to create a network between computers to transmit data packets. Each node has the authority to originate, transmit, and receive messages from other computers. In this case, messages are divided into standardized elements, called "package". Each package is assigned an address, which ensures the correct and complete delivery of documents. In the first version of the theoretical development of the predecessor of the modern World Wide Web, which was released in 1964 thanks to Paul Baran, it was argued that all network nodes should have the same status. This network was called ARPANET, and it was intended to explore various options for ensuring the reliability of communication between different computers. It became the immediate predecessor of the Internet. -Paul Baran - thanks to whom in 1964 the network appeared - the progenitor of the modern Internet.
4 slide
Description of the slide:
For eight years, DARPA worked on the project, and in 1969, the Department of Defense approved ARPANET as the leading research organization in the field of computer networks. From that time, nodes began to be created new network. As early as next year, ARPANET hosts were using NCP to exchange. A year later, the network already had 15 nodes. 1972 is the year in which the addressing design teams were created to harmonize different protocols. At the same time, TCP / IP data transfer protocols were developed. In 1973, the first international connections were made. The countries that entered the ARPANET network were England and Norway. The ARPANET project turned out to be so successful that soon many organizations in the USA, England and Norway wished to join it. The history of the Internet is just beginning. In 1976, they developed the UUCP protocol, and three years later they launched USENET, which works on the basis of UUCP. The US Department of Defense in 1983 declared TCP / IP as its standard. 1984 was the year of the introduction DNS systems, and the total number of hosts exceeded 1000. The formation of CSNET accelerated significantly in 1986, when they began to create supercomputer centers. Already by 1987, the number of hosts had crossed over 10 thousand. And in 1988, NSFNET began using the T1 channel. -DISA - Defense Information Systems Agency - information systems defense agency.
5 slide
Description of the slide:
Internet in Russia. The network went into operation in 1995. In 1996-98, a backbone network was built for science and higher education. At the same time, networks of commercial suppliers emerged and developed. Initially, they focused on connecting organizations. In 1998, Rostelecom formed the Relcom-DS company together with Relcom. Today it is the largest provider of Internet services in Russia. To date, the Internet already has a huge database of information in Russian. According to sociologists, at the end of 1998 in Russia about 1.5 million people were Internet users, more than half of these users lived outside of Moscow. In 1999, the number of users exceeded 5 million.
6 slide
Description of the slide:
The negative impact of the Internet on humans. -Internet and vision. -Computer and bad health. -Internet is addictive.
7 slide
Description of the slide:
1.1 Internet and vision. In fact, it is not the Internet that badly affects vision, but the computer, but the Internet is definitely to blame for this. Let's look at the statistics of those whose vision deteriorates more. This means that those users who communicate on the computer have more likely worsen your vision. Such users communicate using the Internet, which means that the Internet negatively affects our vision. Vision deteriorates due to greater fatigue, when a person sits at a computer for a very long time and continuously, vision weakens. Also, vision deteriorates when reading from the monitor screen. 1.2 Computer and bad health. A person working at a computer for a long time must maintain a relatively immobile position, which negatively affects the spine and blood circulation throughout the body (blood stasis). Long work on the keyboard leads to overstrain of the joints of the hand and the muscles of the forearm. Working at a computer involves processing a large amount of information and constant concentration of attention, therefore, with prolonged work at a computer, mental fatigue and impaired attention often develop. Working at a computer often absorbs all the attention of a working person, and therefore, such people often neglect normal nutrition and work from hand to mouth all day. This is directly related to the Internet, because a person at a computer will spend more time only when he is on the Internet, a person will absorb a large number of information, communication, and he will lose track of time, and health will deteriorate every minute. 1.3 The Internet is an addiction. Computer addiction is no less dangerous than drug addiction, as it leads to a significant violation of adaptation in society (inability to work, inability to start a family or simply serve oneself). Internet addiction is a mental disorder, an obsessive desire to connect to the Internet and a painful inability to disconnect from the Internet in time.
8 slide
Description of the slide:
The positive impact of the Internet on people. Positive features of the influence of the Internet on a person - Earnings in the network, job search. - Ability to pay, order many services via the Internet. - Show yourself to the world. - Communicate with people, find old friends, classmates. - On the Internet, you can always get the latest news on any topic.
9 slide
Description of the slide:
We have considered some of the negative aspects of the Internet, but you can also find positive ones. We can communicate with people who are thousands of kilometers away, we can exchange information at a distance, we can make all kinds of purchases without leaving home, etc. Let's consider the useful features of the Internet. 2.1Purchases over the Internet. Now it is becoming very popular to purchase through online stores, you choose the product you need, put it in the online basket and pay with a card, ATM or web wallet. It is very comfortable. 2.2Internet money. Now at this time it has become popular to have an online wallet. This is a kind of wallet, but we cannot see or touch it. it is in interactive space. It is visual, but the money that is in it is a real means of payment. With this money, we can pay for other goods from online stores. And these are just the main advantages. The needs and demands of Internet users are very different. Some want to get something new software. Others are looking for certain documents they need for their professional activities. Still others connect to the network to receive e-mail. The Internet helps everyone.
10 slide
Description of the slide:
Bozhenko Anastasia
The presentation contains information about the basics of the global computer network Internet
Download:
Preview:
To enjoy preview presentations create an account ( account) Google and sign in: https://accounts.google.com
Slides captions:
Global computer network "Internet" Completed by: 9th grade student Anastasia Bozhenko Supervisor: teacher of computer science and ICT Yaltantseva V.V. SCOU RO boarding school of the 5th type in the city of Zernograd
Plan The history of the emergence of global computer networks The basic concept of global computer networks Equipment used in global networks Internet connection Internet services (services) Terminal mode E-mail Usenet teleconferences World Wide Web service Domain Name System (DNS) FTP file transfer service Gopher shell Instant messaging services and instant messengers
The history of the appearance of global computer networks In 1969, the ARPAnet computer network was created in the United States, uniting the computer centers of the Ministry of Defense and a number of educational organizations. On January 1, 1983, the ARPANET switched to the TCP / IP protocol stack, which is still successfully used to connect networks. It was in 1983 that the term "Internet" was assigned to the ARPANET.
Basic concepts of global computer networks The Internet is a global computer network that unites many local, regional and corporate networks and includes tens of millions of computers. The official birth date of the Internet is January 1, 1983. On this day, it was decided to transfer the ARPA network to the TCP / IP protocol. The Jargon File gives the "date of birth of the Internet" 1969, the transition from NCP/IP to TCP/IP - 1982, the appearance of the first DNS - 1983.
TCP / IP protocol The TCP / IP protocol has many features that give it an advantage over other protocols: the ability to fragment packets a flexible addressing system that makes it easier to include networks of other technologies in the global network
Global network equipment Modem - a device for interfacing a computer with telephone line, which receives signals from a computer and converts them into a suitable telephone network shape and vice versa. Types of modems: internal - has the form of a board built inside system block PC; external - a separate device connected, on the one hand, to one of the PC connectors, and on the other hand, to the telephone network.
Connecting to the Internet using ADSL technology ADSL (Asymmetric Digital Subscriber Line - asymmetric digital subscriber line) is a technology that turns standard analog telephone lines into high-speed access lines. This connection, despite some of its shortcomings, remains the most popular today.
Wireless Internet Wi - Fi connection (Wireless Fidelity - "wireless accuracy") is very convenient and fast enough (up to 100 Mbps). To set up a connection to the Internet via Wi-Fi, you will need special equipment. Firstly, the computers you want to connect must have receivers installed (most modern laptops have them built in), and to create your own wireless network, you will need devices that “distribute the Internet” (access points).
Mobile Internet This connection very convenient when you need to access the Internet away from telephone sockets or outside the coverage area of a Wi-Fi network. Today the leading mobile operators There are special USB modems into which a SIM card is inserted. Looks this device like a regular flash drive.
4G Internet Connecting to the Internet using this technology is quite simple: it is enough to have a special 4G modem device. The only difficulty is the small coverage area of these networks, in contrast to mobile communications. Whatever Internet connection you choose, the main thing is to make it safe. If you are using wireless Wi-Fi networks, Remember that the network must be password protected, otherwise anyone within range of the network can freely use your Internet connection.
Internet Services Telnet World Wide Web E-mail Usenet newsgroups Domain Name System (DNS) File Transfer Service FTP Gopher Shell Instant Messaging and Messenger Services
telnet This service provides interaction with remote computer. By establishing a connection using Telnet, the user gets the opportunity to work with a remote computer, as with "his own". The Telnet service has not been used by most users lately. Many information systems previously accessible exclusively via Telnet are now accessible from the World Wide Web.
WWW (World Wide Web) In 1991, the European Laboratory for Particle Physics (CERN) in Switzerland announced the creation of a new global information environment, the World Wide Web. The creation of the World Wide Web, based on hypertext technology and the HTTP application protocol for transmitting Web pages, is a major event in Internet history. Web pages are created using a special HTML language. WWW (World Wide Web) is the most popular service on the Internet. WWW is the basis of the Internet, it is a distributed system of hypermedia (hypertext), in which documents are hosted on Internet servers and linked to each other by links.
E-mail (E-Mail) E-mail is similar to regular mail, and it is very easy to get used to using it. Typically, email reaches anywhere in the world in a matter of minutes. Just like a fax, it allows you to send not only text, but also an image, but you do not use long-distance or international telephone connection, and the image quality does not deteriorate during transmission.
Usenet Usenet is a computer network used to communicate and publish files. Usenet consists of newsgroups to which users can post messages. Messages are stored on servers that exchange them with each other. Usenet has had a great influence on the development of modern web culture, giving rise to such widely known concepts as "nickname", "smiley", "signature", "moderator", "trolling", "flood", "flame", "ban" , "FAQ" and "spam". Usenet is part of the Internet, not a separate network. Usenet is accessed via the NNTP protocol.
Domain Name System (DNS) DNS (English Domain Name System - domain name system) - a computer distributed system for obtaining information about domains. Most commonly used to obtain an IP address from a host name (computer or device), obtain information about mail routing, serving hosts for protocols in a domain (SRV record). A distributed DNS database is supported by a hierarchy of DNS servers that communicate over a specific protocol.
FTP Service The FTP service is widely used for file sharing on the Internet and local networks. It runs on a specialized FTP protocol (file transfer protocol), which is intended only for file transfer and is well suited for this task.
Gopher Shell Gopher is an Internet capability integrator. It allows you to use all the services provided by the Internet in a convenient form. The shell is organized in the form of many nested menus at different depths, so you just have to select the desired item and press enter. Everything your heart desires is available in this form: telnet sessions, ftp sessions, e-mail, etc. and so on. Also included in this shell are interfaces with such servers, with which it is simply impossible to communicate manually due to their machine-oriented protocol.
Instant Messaging and Messenger Services IRC (Internet Relay Chat or Chat) is the first online communication tool that provides a large selection of channels (topics) for discussions with like-minded people. Chat is a text dialogue in real scale time. IMS (Instant Messaging Service) is one of the technologies that provides communications on the Internet. In the instant messaging service, in addition to text messages, you can send audio signals, pictures, videos, files.
Most popular messengers ICQ (I Seek You - I'm Looking For You) is a popular program (the most common Internet pager) for real-time communication. Skype is the world's most widely used closed protocol messenger. Allows you to call landlines and Cell phones, receive calls. The "Video Call" function allows you to talk and share full-screen video from Webcams installed by users. Miranda IM is an open-source multi-protocol instant messaging messenger for working on the Internet or a local network.
CONCLUSION Until quite recently, the Internet seemed to be something strange, mysterious and inaccessible. Now the situation has changed - you can easily access the Global Network from almost any computer, phone and even TV, there are also models that have a browser and can show you a movie online or help you chat via Skype ... According to the latest statistics, more than 2, 5 billion people use the Internet every day. If the total population of the Earth is 8 billion, then approximately 30% visit the Internet daily. In Russia, in 2014, the number of Internet users increased by 2.5 million people: today, 62% of the country's population use the network.
sources http://page.cherepovets.ru/~alko-service/pages/network.html http://www.lessons-tva.info/edu/telecom-glob/glob.html http://info-tehnologii. ru/Komp_seti/slugba_internet/index.html http://eco.sutd.ru/Study/Informat/W98/Net.html https://ru.wikipedia.org/wiki/Usenet www.rusadvice.org https:// en.wikipedia.org/wiki/DNS http://citforum.ru/internet/klimenko/glava_4.shtml http://www.lessons-tva.info/edu/trainbus/1_2.html
- Except local networks also exist:
- A corporate network is an association of local networks within a single corporation.
- A regional network is an association of computers and local networks to solve common problems regional scale.
- The need for the formation of a single global information space led to the creation of the global computer network Internet.
- The global network is an association of computers located at a remote distance for general use world information resources.
- Internet
- inter- "between"
- net, network- "net"
- The Internet is a global computer network that unites many local, regional and corporate networks and includes tens of millions of computers.
- Turning to the Internet, we use the services of an Internet provider. The provider connects clients to its network, which become part of the provider's network and at the same time part of all the interconnected networks that make up the Internet.
- In order for computers to find each other in the process of exchanging information, there is a unified addressing system on the Internet based on the use of an IP address.
- Every computer connected to the Internet has its own unique 32-bit (binary) IP address.
- The total number of IP addresses is over 4 billion:
- N=232=4294967296
- The address of a computer on a network is called an IP address.
- General form:
- XXX.XXX.XXX.XXX
- octets
- octets
- An IP address consists of four parts written as dotted decimal numbers (for example, 192.168.1.1). Each of these four parts is called an octet. An octet is eight binary digits (for example, 11000000, or 192 in decimal). Thus, each octet can take on binary values from 00000000 to 11111111, or from 0 to 255 in decimal. The following figure shows an example of an IP address where the first three octets (192.168.1) are the network number and the fourth octet (16) is the host ID.
- Host - any computer connected to the Internet, regardless of its purpose.
- 195.85.102.14
- 195th subnet of the Internet
- 85th subnet 195th subnet
- 102nd subnet 85th subnet
- 14th computer in 102 subnets
- Domain Name System (DNS)
- DNS converts the numeric IP address of a host (computer) into a set of characters.
- The Internet has a more user-friendly and user-friendly system of addresses, in which the address is indicated by an individual domain name. This is a symbolic name system.
- Each domain name consists of several words separated by dots.
- Domain names are built on a hierarchical basis. The rightmost one is the top-level domain. Further decoding of a domain name is made from right to left.
- Examples of domain names:
- microsoft.com is a commercial organization of the Microsoft Corporation
- www.gov.ru - the official website of the Russian government
- A domain is a group of computers that are grouped together in some way.
- www.qqq.microsoft.ru
- 1st level domain
- 2nd level domain
- 3rd level domain
- 1st level domains (domain zones)
- The first level domain (top level) is 2 - 4 letters that are placed at the end of each domain name after a dot (.ru, .com, .ua, .uz, etc.), and are not used for site names by themselves.
- A second-level domain is obtained by adding the word (website name) before the first-level domain.
- A third-level domain is obtained by adding a word through a dot before the second-level domain.
- There are also fourth-level domains, they are formed according to the same principle, but are used extremely rarely. Fourth-level domain names are quite long and complex, and their names are hard to remember.
- In addition, first-level domain names can be divided into national (geographic) domains, and general use domains (ie, for sites of a certain orientation).
- Examples of geographic domain zones:
- .ru - Russian Federation
- .rf - Russian Federation
- .ua– Ukraine
- .uz – Uzbekistan (domain name registration in Uzbekistan)
- .kz - Kazakhstan
- .am - Armenia
- Examples of public domain zones:
- .info - information nodes.
- .net - providing networking
- .org - non-profit organizations
- .biz - commercial organizations
- .com - commercial
- .gov - government
- http:// - Hyper Text Transfer Protocol;
- www - World Wide Web - World Wide Web;
- myhost.mydomain - third-level domain;
- spb - second-level domain;
- Ru is the first level domain.
- Internet packet routing ensures that information is delivered from the sending computer to the receiving computer.
- Data is transported by splitting files into Internet packets on the sending computer, routing each packet individually, and reassembling the files from the packets in their original order on the receiving computer.
- To interact with each other on the Internet computers different types and varied OS use various protocols - sets of rules and agreements that describe exactly how data is transmitted over the network.
- The Internet functions and develops thanks to the use of a single data transfer protocol TCP/IP. The term TCP/IP includes the names of two protocols:
- Transmission Control Protocol (TCP)
- Internet Protocol (IP)
- The TCP/IP protocol provides for the transfer of information between computers on a network. In order for the letter to reach its destination, the information is packed into an "envelope" on which the IP addresses of the recipient's and sender's computers are "written". For example, "To: 198.78.213.165", "From: 193.124.5.33". The contents of the envelope in computer language is called an IP packet and is a collection of bytes.
- IP packets on their way to the receiving computer also pass through numerous intermediate Internet servers, on which the routing operation takes place. As a result of routing, IP packets are sent from one Internet server to another, gradually approaching the recipient computer. Computers that forward, receive, and route packets must follow the same strict rules in order to act quickly and smoothly. The set of these rules for the Internet is the Internet Protocol (IP)
- On the Internet, a situation often occurs when you need to send a multi-megabyte file. In such cases, on the sending computer, it is necessary to split a large file into small parts, number them and transport them in separate IP packets to the receiving computer. On the receiving computer, you need to assemble the source file from separate parts. All these actions are performed on the basis of the Transmission Control Protocol, i.e. the transport protocol.
Composition of the Internet 2 WWW. (World Wide Web) E-mail () File servers (FTP) Teleconferencing (UseNet) Real-time communication systems (ICQ)
WWW - World Wide Web 3 World Wide Web (World Wide Web) - is Information system, the main components of which are hypertext documents (pages created using the HTML hypertext markup language). Web documents are accessed using web servers. The virtual world of the WWW is populated by millions of documents residing on hundreds of thousands of servers. The task of the WWW-traveler is to find among them the one that contains the necessary information and read it using the viewer - and for this the viewer must know the exact location this document. It is uniquely identified by the server address, port number, directory name, and file name with this document.
4 In order to navigate the Web, you need a browser program that can establish a connection with the server on which the website is located and provide the user with access to its resources. Such programs are called browsers, or navigators. In order to navigate the Web, you need a browser program that can establish a connection with the server on which the website is located and provide the user with access to its resources. Such programs are called browsers, or navigators. The most common navigators are Internet Explorer by Microsoft and Netscape Navigator by Netscape. Web document addresses (URLs) locate resources on the Internet and share the same basic structure.
5
6 A protocol is a set of rules by which client-server interaction takes place. The "native" WWW protocol is called http. In addition to http, WWW clients can communicate with servers that support the ftp, gopher, and some other protocols. The protocol name is separated from the rest of the URL by a colon. In the protocol name, uppercase Latin letters and their corresponding lowercase letters are equivalent.
7 Server address: The beginning of the address is marked with two slashes //. It consists of several parts (not necessarily four, as in our example) - the so-called subdomains. Subdomains, which are combinations of letters and numbers, are separated by dots, and the "reference of addressee coordinates" from larger to smaller subdomains occurs from right to left. As in the name of the protocol, in the server address, uppercase Latin letters and their corresponding lowercase letters are equivalent
Edu is a top level domain. It denotes either a country code or, as in this case, a network code. edu is the network code for higher educational institutions USA. The following top-level domains are also often found: gov - US government organizations, mil - US military, com - commercial organizations, net - network services Internet, org - non-profit organizations, su - CIS countries, ru - Russia.
Uiuc.edu is a second-level subdomain. Second-level subdomain names are approved in accordance with the rules developed by top-level domains. In this case, the abbreviation means University of Illinois at Urbana-Champaign.
Scs.uiuc.edu is a third level subdomain. Third-level subdomain names are approved in accordance with the rules developed by second-level domains. In our example, scs means School of Chemical Sciences.
Subdomain of the fourth, in this case, the youngest level. Likewise, fourth-level subdomain names are approved according to rules developed by third-level domains. In our example, the subdomain is named www because the WWW server is located on this machine.
12 The port number is expressed as a positive integer and is separated from the address by a colon. A port is like a "door" through which you can enter the server. A server may have multiple ports available; if the WWW server port number is 80, then it can be omitted from the URL.
Electronic mail 15 Electronic mail (English, from English electronic mail) technology and the services it provides for sending and receiving electronic messages(called "letters" or "e-mails") over a distributed (including global) computer network. Email-it's normal text file, containing email address recipient and text of the letter.
16
Work with email Inbox - contains letters received by the addressee; Outbox - contains letters sent by the addressee, from the moment they were created until the moment they were delivered from local computer to the mail server Sent - contains all messages delivered to the mail server; Deleted - contains deleted messages; Drafts - contains letter drafts. 17
Mailbox Mailbox is a section external memory mail server reserved for the subscriber. The mailbox has a unique name; the owner has access to his mailbox via password: 18
Email exchange rules. The email should not contain a large text message, if necessary, it is better to attach a text file; Attached letters must have the volume in accordance with the instructions; Be sure to use archivers to pack attachments; To enhance the emotionality of the letter, you must use emoticons. 20
Teleconference 22 Teleconference: comfortable communication Communication is the interaction of individuals or social groups, which consists in joint activities, direct exchange of skills, abilities, experience, information and satisfies the needs of a person in contacts with other people. A teleconference (UseNet) is a system for exchanging information between multiple users.
On-line communication 23 On-line communication systems (chat? ICQ) are specialized tools that allow real-time communication between users via computer communication channels. Chat (English chat to chat, chatter, conversation) is a means of exchanging messages over a computer network in real time, as well as software that allows you to organize such communication. characteristic feature is communication in real time or close to it, which distinguishes chat from forums and other "slow" means. The word chat usually refers to group communication, although one-on-one text exchange through instant messaging programs, such as ICQ or even SMS, can also be included. Chat (English chat to chat, chatter, conversation) is a means of exchanging messages over a computer network in real time, as well as software that allows you to organize such communication. A characteristic feature is communication in real time or close to it, which distinguishes chat from forums and other "slow" means. The word chat usually refers to group communication, although one-on-one text exchange through instant messaging programs, such as ICQ or even SMS, can also be included. Databases with remote access 28 People's Library Biographies of famous people Science and education Collection of essays
30
