1. Living Online Module Lesson 23 — Networks and Telecommunication
Computer Literacy BASICS

2. Computer Literacy BASICS
Objectives
Describe a network.
Explain the benefits of a network.
List and describe the types of networks.
Explain the advantages and disadvantages of networked computing.
List and describe communications media.
Computer Literacy BASICS

3. Computer Literacy BASICS
Objectives (cont.)
Describe communications hardware.
Describe network architecture.
Describe communications software.
Computer Literacy BASICS

4. Computer Literacy BASICS
Vocabulary
Bridge
Client
Client/server network
Communications channel
Extranet
Gateway
Hub
Intranet
Computer Literacy BASICS

5. Computer Literacy BASICS
Vocabulary (cont.)
Modem
Network interface cards (NICs)
Peer-to-peer network
Router
Server
Transmission media
Computer Literacy BASICS

6. Computer Literacy BASICS
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.
An endpoint of a network connection, such as a computer terminal, server, or printer, is called a node.
Computer Literacy BASICS

7. Computer Literacy BASICS
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).
Most WANs are made up of several LANs.
The transmission of data from one location to another is called data communications.
Computer Literacy BASICS

8. Components Required for Data Communications
A sending device, which is generally a computer
A communications device, such as a modem, that converts the computer signal into signals supported by the communications channel
A communications channel or path, such as telephone lines, cable, or a wireless transmission link, over which the signals are sent
A receiving device that accepts the incoming signal, which is generally a computer
Communications software
Computer Literacy BASICS

9. Communications Components
Computer Literacy BASICS

10. Computer Literacy BASICS
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 Literacy BASICS

11. Computer Literacy BASICS
Communications Media
Sending data from one computer to another requires a channel, the link through which the message is sent.
A phone line or cable serves as a channel.
You also need a device on each end of the channel to convert the computer signal to a signal type that the channel can send.
A modem is a conversion device.
Computer Literacy BASICS

12. Computer Literacy BASICS
Transmission Media
Sending a message through the channel requires a transmission media, which can be physical or wireless.
Examples of physical media include twisted-pair cable, coaxial cable, and fiber-optic cable.
Examples of wireless media include radio signals, microwave signals, and satellite transmissions.
Computer Literacy BASICS

13. Types of Physical Media
Twisted-pair cable
Coaxial cable
Fiber-optic cable
Computer Literacy BASICS

14. Types of Wireless Media
Satellite transmissions
Microwave towers
Computer Literacy BASICS

15. Computer Literacy BASICS
Network Hardware
Most networks consist of a server and multiple client computers.
They also include two other categories of hardware:
Communications hardware to facilitate the transmitting and receiving of data
Network transmission hardware to connect the cabling and amplify signals as they travel across the network.
Computer Literacy BASICS

16. Communications Hardware
A modem converts analog signals to digital and vice versa.
Modems enable a computer to send data over a standard phone line.
The sending computer and the receiving computer must both have modems.
Cable modems use coaxial cable to send data over cable television lines.
These have much faster transmission rates than a standard telephone line modem.
Computer Literacy BASICS

17. Communications Hardware: A Computer with Attached Modem
Computer Literacy BASICS

18. Network Transmission Hardware figure
Network Interface Cards (NICs): All computers in a LAN must have a NIC, which enables and controls the sending and receiving of data between the computers.
Hub: Receives and sends signals back out
Bridge: Connects one LAN to another LAN
Gateway: Links networks using different protocols
Router: Connects multiple networks and determines the fastest route for sending data over the network
Computer Literacy BASICS

19. Network Transmission Hardware: Computers Connected to a Hub
Computer Literacy BASICS

20. Computer Literacy BASICS
Local Area Networks
Local area networks (LANs) are usually confined to a limited area.
Most LANs connect computers and peripherals, such as printers or scanners.
The two most popular LANs are
Client/server
Peer-to-peer
Computer Literacy BASICS

21. A Client/Server Network
A computer (or more than one computer) called a server manages the network resources for all of the devices on the network.
Computer Literacy BASICS

22. A Peer-to-Peer Network
All of the computers on a peer-to-peer network are equal—there is no server, and people on the network each deter-mine what files they will share with others on the network.
Computer Literacy BASICS

23. Computer Literacy BASICS
Wide Area Networks
Wide area networks (WANs) cover a large geographical area such as a city, a state, a country, or the world.
Most WANs consist of two or more LANs connected by routers.
Two types of WANs are
Intranets
Extranets
Computer Literacy BASICS

24. Computer Literacy BASICS
Intranets
An intranet is designed for the exclusive use of people within an organization.
Many businesses have intranets that they use to make files, such as handbooks and employee manuals, newsletters, and employment forms, available to company employees.
An intranet may use HTML files and browsers to create and view documents on the network.
Computer Literacy BASICS

25. Computer Literacy BASICS
Extranet
An extranet is similar to an intranet, but it allows specified users outside of the organization to access internal information systems.
Like the Internet, extranets utilize and support Web technologies, such as hyperlinks and Web pages, coded in hypertext markup language (HTML).
Computer Literacy BASICS

26. Network Operating Systems
Networks require a network operating system (NOS) and a desktop operating system.
The NOS runs on the server and provides
Network administration tools
Print services
Client services
Security services
Computer Literacy BASICS

27. Computer Literacy BASICS
Summary
A network is a group of two or more computers linked together.
A local area network is generally confined to a limited geographical area.
A wide area network is made up of several connected local area networks.
Data communications is the transmission of data from one location to another.
Computer Literacy BASICS

28. Computer Literacy BASICS
Summary (cont.)
The Internet is the biggest network of all.
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 Literacy BASICS

29. Computer Literacy BASICS
Summary (cont.)
Physical media includes twisted-pair cable, coaxial cable, and fiber-optic cable.
Wireless media includes radio signals, microwaves, and satellite transmission.
Most networks consist of a network server and computer clients.
A modem is a type of communication device.
Computer Literacy BASICS

30. Computer Literacy BASICS
Summary (cont.)
Network interface cards enable the sending and receiving of data between PCs in a LAN.
A hub is a device that controls the incoming and forwarding of data.
A bridge connects one LAN to another.
A gateway links two different types of networks.
Computer Literacy BASICS

31. Computer Literacy BASICS
Summary (cont.)
A router directs traffic on the Internet or on multiple connected networks.
The two popular types of LANs are the client/server network and the peer-to-peer network.
Networks require network operating system software.
Computer Literacy BASICS

32. Computer Literacy BASICS
Vocabulary
Bridge :Connects one LAN to another LAN
Client: Is a computer on the network that request and shares the resources from the server.
Client/Server n/w: It is a network that has one/more server and user computers known as clients.
Communication :A link through which the data can be transmitted.
Computer Literacy BASICS

33. Computer Literacy BASICS
Extranet: An extranet is similar to an intranet, but it allows specified users outside of the organization to access internal information systems.
Gateway: Links networks using different protocols.
Hub: Receives and sends signals back out.
Intranet: An intranet is designed for the exclusive use of people within an organization
Computer Literacy BASICS

34. Computer Literacy BASICS
Modem: A communications device, that converts the computer signal into signals supported by the communications channel.
NIC(Network Interface card): enables sending and receiving of data between PC’s in a LAN.
Peer to Peer Network: on a peer-to-peer network are equal—there is no server, and people on the network each deter-mine what files they will share with others on the network
Computer Literacy BASICS

35. Computer Literacy BASICS
Router: A router directs traffic on the Internet or on multiple connected networks.
Server: Is a centralized computer that manage network resources.
Transmission media: Sending a message through the channel requires a transmission media, which can be physical or wireless.
Computer Literacy BASICS

36. Computer Literacy BASICS
Router
MICROWAVE
NIC
Computer Literacy BASICS

37. Communication Hardware
Computer Literacy BASICS