A computer network is a series of connections and associated devices through which computers can communicate with other computers. A computer network consists of two or more computers that are interconnected in order to share resources (such as printers), exchange files, or allow electronic communications. In a computer network the individual stations, called "nodes", may be computers, terminals, or communication units of various kinds. The computers on a network may be linked through cables, telephone lines, radio waves, satellites, or infrared light beams.
In addition to physically connecting computers and communication devices, a network system has the function of establishing a cohesive architecture that allows almost seamless data transmission while using various equipment types. Open System Interconnection (OSI) and IBM's System Network Architecture are two popular architectures used at present.
Local-area networks and wide-area networks are two basic network types.
A local-area network (LAN) is a computer network that covers a local area. It may be a home, office or small group of buildings such as a college or factory. The topology of a network dictates its physical structure. The generally accepted maximum size for a LAN is 1 square km. At present, there are two common wiring technologies for a LAN, Ethernet and Token Ring. A LAN typically includes two or more PCs, printers, CD-ROMs and high-capacity storage devices, called file servers, which enable each computer on the network to access a common set of files. A LAN is controlled by LAN operating system software. LAN users may also have access to other LANs or tap into wide-area networks. LANs with similar architectures are linked by transfer points, called "bridges", and LANs with different architectures use "gateways" to convert data as it passes between systems. A router is used to make the connection between LANs.
A wide-area network (WAN) is a computer network that covers a wide geographical area, involving a large number of computers. Computer networks may link the computers by means of cables, optical fibres, or satellites and modems. Typically, WANs are used to connect LANs together. Many WANs are built for one particular organization and are private, others, built by Internet service providers, provide connections from an organization's LAN to the Internet. WANs are most often built of leased lines. At each end of the leased line, a router is used to connect to the LAN on one side and a hub within the WAN on the other.
The best example of a WAN is the Internet, a collection of networks and gateways linking millions of computer users on every continent. Networks within the Internet are linked by common communication programs and protocols. A protocol is a set of established standards that enable computers to communicate with each other. A number of network protocols such as TCP/IP,X.25, ATM and Frame relay can be used for WANs. By means of the Internet, users can obtain a variety of information browsing via buttons, highlighted text, or sophisticated searching software known as search engines.
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Task 2. Answer the questions.
1. What is a computer network?
2. What does a computer network consist of?
3. What are computers on a network connected for?
4. What is a node in a computer network?
5. How may the computers on a network be linked?
6. What function does a network system have in addition to physically connecting computers and communication devices?
7. What are the two popular architectures used at present?
8. What is a local-area network?
9. What dictates the physical structure of a network?
10. What is the generally accepted maximum size for a LAN?
11. What wiring technologies for a LAN are there at present?
12. What does a LAN typically include?
13. What is a LAN controlled by?
14. What may LAN users have access to?
15. What is a bridge?
16. What is a gateway?
17. What is a router used for?
18. What is a wide-area network?
19. How may computer networks be linked?
20. What are WANs typically used for?
21. What do WANs built by Internet providers provide?
22. What are WANs most often built of?
23. What is the Internet?
24. What are networks within the Internet linked by?
25. What is a network protocol?
Task 3. Give synonyms (a) and antonyms (b) for the words below:
a) tap into sth, allow, link, cover (), area, variety, seamless, various, common, topology, particular, typically, via;
b) transmission, highlight, allow, enable, cover (), accept, variety, individual, various, different, particular, generally, connect.
Task 4. Which of the sentences below are true and which of them are false? Correct the false ones.
1. Increasing processing speed is the main idea of a computer network.
2. In a computer network the individual stations, called "nodes", may be computers, terminals, or communication units of various kinds.
3. The computers on a network may be linked through a communications network called a bus.
4. In addition to physically connecting computers and communication devices, a network system has the function of establishing a cohesive architecture that allows converting data as it passes between systems.
5. Ethernet and Token Ring are two popular network architectures used at present.
6. A local-area network is a computer network that covers a local area.
7. The size of a network dictates its physical structure.
8. The generally accepted maximum size for a LAN is 1 square mile.
9. A LAN typically includes two or more PCs, printers, CD-ROMs and high-capacity storage devices, called transfer points, which enable each computer on the network to access a common set of files.
10. A LAN is controlled by LAN operating system software.
11. LANs with similar architectures are linked by transfer points, called "nodes", and LANs with different architectures use "bridges" to convert data as it passes between systems.
12. A hub is used to make the connection between LANs.
13. A wide-area network is a computer network that covers a wide geographical area, involving a large number of gateways.
14. Computer networks may link the computers by means of cables, optical fibres, or satellites and modems.
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15. Typically, WANs are used to connect LANs together.
16. Many WANs are built for one particular organization and are personal, others, built by Internet service providers, provide connections from a persons LAN to the Internet.
17. WANs are most often built of leased lines.
18. At each end of the leased line, a hub is used to connect to the LAN on one side and a modem within the WAN on the other.
19. The Internet is a collection of routers and bridges linking millions of computer users on a particular continent.
20. A protocol is system software that enables computers to access a set of common files.
Task 5. Give Ukrainian equivalents of the following English word-groups:
to consist of two or more computers; in order to share resources; to exchange files; to allow electronic communications; individual stations; communication units of various kinds; computers on a network; infrared light beams; in addition to physically connecting computers; the function of establishing a cohesive architecture; to allow almost seamless data transmission; various equipment types; at present; to cover a local area; file server; the generally accepted maximum size for a LAN; two common wiring technologies; to access a common set of files; to tap into wide-area networks; LANs with similar/different architectures; particular organization; Internet service providers; to provide connections from an organizations LAN to the Internet; to be built of leased lines; a collection of networks and gateways; millions of computer users on every continent; networks within the Internet; established standards; to enable computers to communicate with each other; a number of network protocols;
by means of the Internet; a variety of information; to browse via buttons and highlighted text; sophisticated searching software known as search engines.
Task 6. Give English equivalents of the following Ukrainian word-groups:
; ; ; ; -; ; ; ; 㳿 璺; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; 璺 ; ; , ; ; ; ; ; ; / .
Task 7. Complete the sentences by properly using the words given in brackets below. Mind the correct grammar form!
1. A computer network computers.
2. The may be linked cables, telephone lines, radio waves, satellites, or infrared light beams.
3. physically connecting computers and communication devices, a network system has the function of a cohesive architecture that data transmission while using various equipment types.
4. A local-area network a local .
5. The of a network its physical structure.
6. , there are two wiring technologies for a LAN, Ethernet and Token Ring.
7. LAN users may also wide-area networks.
8. Many WANs are built for one organization and are private.
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9. The Internet is a of networks and gateways linking millions of computer users on continents.
10. the Internet, users can a variety of information browsing of buttons, highlighted text, or sophisticated searching software known as search engines.
(by means of; be made up of; smooth; widespread; with the help of; all; currently; along with; enable; territory; specify; connect to; creating; set; specific; networked computers; get; by the use; embrace; configuration; multiple)
Task 8. Make up all possible questions to the sentences below.
1. A computer network consists of two or more computers.
2. A local-area network covers a local area.
3. The topology of a network dictates its physical structure.
4. At present, there are two common wiring technologies for a LAN.
5. File servers enable each computer on the network to access a common set of files.
6. A LAN is controlled by LAN operating system software.
7. LAN users may also have access to other LANs or tap into wide-area networks.
8. "Gateways" convert data as it passes between systems.
9. A router is used to make the connection between LANs.
10. WANs are most often built of leased lines.
Task 9: Match the columns in order to complete the definitions.
1. A gateway is an interface...
2. A bridge is a hardware and software combination...
3. A backbone is a network transmission path...
4. A router is a special computer...
5. A network is a number of computers and peripherals...
6. A LAN is a network...
7. A server is a powerful computer...
8. A client is a network computer...
9. A thin client is a simple computer...
10. A hub is an electronic device...
()...connecting computers over a small distance such as within a company.
()...directing messages when several networks are linked.
()...used for accessing a service on a server.
()...connecting all the data cabling in a network.
()...used to connect the same type of networks.
()...comprising a processor and memory, display, keyboard, mouse and hard drives
only.
()...linked together.
()...enabling dissimilar networks to communicate.
()...handling major data traffic.
()...storing data shared by all the clients in the network.
Task 10. Read the text, write down the words you dont know into your vocabulary and do the exercises below.
