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Unit 1—Computer Basics Lesson 7 Networks.

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Presentation on theme: "Unit 1—Computer Basics Lesson 7 Networks."— Presentation transcript:

1 Unit 1—Computer Basics Lesson 7 Networks

2 Computer Concepts BASICS - 2
Objectives Describe the benefits and disadvantages of networks. List and describe the types of networks. List and describe communications hardware. List and describe communications media. Describe the different network topologies. Describe network architecture and protocols. Computer Concepts BASICS - 2

3 Computer Concepts BASICS - 3
Introducing Networks A network is a group of two or more computers linked together. Most networks have a server that manages the network resources. Most networks have multiple clients, which are computers that access the server. Computer Concepts BASICS - 3

4 Introducing Networks (cont.)
A network confined to a limited geographical area is called a local area network (LAN). A network spread over a wide area is called a wide area network (WAN). The transmission of data from one location to another is called data communications. Computer Concepts BASICS - 4

5 Network Building Blocks
Sending data from one computer to another requires a channel, the link through which the message is sent. A phone line or cable is a channel. A device on each end of the channel converts the computer signal to a signal type that the channel can send/receive. Computer Concepts BASICS - 5

6 Network Building Blocks (cont.)
Sending a message through the channel requires a transmission media, which can be physical or wireless. Computer Concepts BASICS - 6

7 Network Building Blocks (cont.)
This figure shows the main components required for data communications: a sending device, a receiving device, a communication path or channel, a device to convert the signal so that the channel can carry it, and the soft-ware to send and receive messages. Computer Concepts BASICS - 7

8 Computer Concepts BASICS - 8
Network Benefits Networks provide almost instant communication with other users on the network. Users can share information. Users can share hardware. Users can share software. Users can work on group projects. Computer Concepts BASICS - 8

9 Network Disadvantages
Data security and unauthorized access are disadvantages of a network. Other disadvantages are Malicious code Network faults Setup and management costs Computer Concepts BASICS - 9

10 Computer Concepts BASICS - 10
Types of Networks Two of the more common types of networks Local area networks (LANs) Wide area networks (WANs) Computer Concepts BASICS - 10

11 Computer Concepts BASICS - 11
Local Area Networks Local area networks usually are confined to a limited area. The two most popular LANs are Client/server Peer-to-peer Computer Concepts BASICS - 11

12 Client/Server vs. Peer-to-Peer
Computer Concepts BASICS - 12

13 Computer Concepts BASICS - 13
Wide Area Networks Wide area networks are spread across a city, a state, the country, or the world. Most WANs consist of two or more LANs connected by routers. Some WANs may be configured as intranets or extranets. Computer Concepts BASICS - 13

14 Other Types of Networks
Metropolitan area network (MAN) Neighborhood area network (NAN) Personal area network (PAN) Home area network (HAN) Campus area network (CAN) Computer Concepts BASICS - 14

15 Computer Concepts BASICS - 15
Network Hardware Most networks consist of a server and multiple client computers. They also include two other categories of hardware: communications hardware and network transmission hardware. Computer Concepts BASICS - 15

16 Network Hardware (cont.)
Communications hardware These devices facilitate the transmitting and receiving of data. Network transmission hardware These devices connect the cabling and amplify. Computer Concepts BASICS - 16

17 Communications Hardware
Modems: Convert analog signals to digital and vice versa Dial-up modems enable a computer to send data over a standard phone line. The sending computer and the receiving computer must both have modems. Computer Concepts BASICS - 17

18 Communications Hardware (cont.)
Modems (cont.) Cable modems use coaxial cable to send data over cable TV lines. These have much faster transmission rates than a standard telephone line modem. DSL and ISDN modems use telephone lines. Computer Concepts BASICS - 18

19 Communications Hardware (cont.)
Network interface cards (NICs) All PCs in a LAN must have a NIC. Gateway Links networks using different protocols Router Connects multiple networks and determines the fastest route for sending data over the network Computer Concepts BASICS - 19

20 Communications Hardware (cont.)
Wireless access point Connects wireless communication devices Hub Receives and sends signals back out Computer Concepts BASICS - 20

21 Computer Concepts BASICS - 21
Communications Media Physical media types Twisted-pair cable Coaxial cable Fiber-optic cable Wireless media types Radio signals Microwaves Satellites Computer Concepts BASICS - 21

22 Communications Media (cont.)
Twisted pair Coaxial Fiber-optic Computer Concepts BASICS - 22

23 Computer Concepts BASICS - 23
Wireless Media Microwaves Satellites Computer Concepts BASICS - 23

24 Other Communications Media
IrDA Infrared transmission Requires line of site Bluetooth Uses radio waves Short distance transmission of about 30 feet WI-FI Wireless fidelity; wireless transmission Computer Concepts BASICS - 24

25 Computer Concepts BASICS - 25
Bluetooth Technology Computer Concepts BASICS - 25

26 Computer Concepts BASICS - 26
Network Topologies A topology is the geometric arrangement of the network. The most common topologies are Bus: All devices are connected to a master cable. Ring: Similar to a bus except that the devices are connected in a circle Star: All devices are connected to a central hub or computer. Computer Concepts BASICS - 26

27 Computer Concepts BASICS - 27
Bus Topology Computer Concepts BASICS - 27

28 Computer Concepts BASICS - 28
Ring Topology Computer Concepts BASICS - 28

29 Computer Concepts BASICS - 29
Star Topology Computer Concepts BASICS - 29

30 Communications Protocols
A protocol is a set of rules that allows computers to exchange data. The protocol determines How a sending device indicates it has finished sending How a receiving device indicates the message was received The type of error-checking to use Computer Concepts BASICS - 30

31 Communications Protocols (cont.)
The most common protocols are Ethernet: Most common LAN protocol Token ring: Also used on LANs TCP/IP: Used on the Internet Computer Concepts BASICS - 31

32 Network Operating Systems Software
Networks require a network operating system (NOS) and a desktop operating system. The clients run the desktop OS. The NOS runs on the server and provides Network administration tools Print services Client services Security services Computer Concepts BASICS - 32

33 Computer Concepts BASICS - 33
Summary Data communication is the transmission of data from one location to another. A network is a group of two or more computers linked together. The Internet is the biggest network of all. Networks have advantages and disadvantages. Computer Concepts BASICS - 33

34 Computer Concepts BASICS - 34
Summary (cont.) A local area network generally is confined to a limited geographical area. A wide area network is made up of several connected local area networks. The two popular types of LANs are the client/server network and peer-to-peer network. Computer Concepts BASICS - 34

35 Computer Concepts BASICS - 35
Summary (cont.) Other types of specialized networks include metropolitan area networks (MANs), neighborhood area networks (NANs), personal area networks (PANs), home area networks (HANs), and campus area networks (CANs). Computer Concepts BASICS - 35

36 Computer Concepts BASICS - 36
Summary (cont.) You can use a network for information sharing, hardware sharing, software sharing, and as a collaborative environment. The link through which data is transmitted is the communications channel. Transmission media can be either physical or wireless. Computer Concepts BASICS - 36

37 Computer Concepts BASICS - 37
Summary (cont.) Physical media includes twisted-pair cable, coaxial cable, and fiber-optic cable. Wireless media includes radio signals, microwaves, and satellites. Most networks consist of a network server and computer clients. Computer Concepts BASICS - 37

38 Computer Concepts BASICS - 38
Summary (cont.) Communication devices facilitate the transmitting and receiving of data, instructions, and information. Communication devices include dial-up and cable modems, DSL and ISDN modems, network interface cards, gateways, routers, wireless access points, and hubs. Computer Concepts BASICS - 38

39 Computer Concepts BASICS - 39
Summary (cont.) Network interface cards enable the sending and receiving of data between the PCs in a network. A router directs the Internet or network traffic. Physical media includes twisted-pair cable, coaxial cable, and fiber-optic cable. Wireless media includes microwaves, satellites, IrDA, Bluetooth, and Wi-Fi. Computer Concepts BASICS - 39

40 Computer Concepts BASICS - 40
Summary (cont.) Network topologies include bus, ring, and star. A protocol is an agreed on set of rules and procedures for transmitting data between two or more devices. The Ethernet protocol is one of the most popular LAN protocols. Computer Concepts BASICS - 40

41 Computer Concepts BASICS - 41
Summary (cont.) Token ring is the second most widely used LAN protocol. TCP/IP is a protocol used by both LANs and WANs to connect to the Internet. All computers on a network require an operating system, and networks require network operating systems. Computer Concepts BASICS - 41

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