1. Lesson 1—Networking BASICS1 Networking BASICS Introduction to Networking Unit 1 Lesson 1

2. Lesson 1—Networking BASICS2 Objectives Define a computer network. List the four purposes of a network. Explain the elements of communication. List and describe the two types of networks.

3. Lesson 1—Networking BASICS3 What Is a Net? A net is made up of individual pieces of rope woven together. Single pieces of rope cannot trap an object. Woven-together pieces form a net that can ensnare objects. The strength of a net comes from the pieces being connected together. “The sum is greater than the parts.”

4. Lesson 1—Networking BASICS4 What Is a Network? A network is anything that resembles a net. Examples include a network of politicians or a network of roads. Like a net, a network accomplishes more through being connected together.

5. Lesson 1—Networking BASICS5 What Is a Computer Network? A computer network is computers and devices connected together. A single computer is limited to its own hardware and software. The capabilities of a computer are increased when connected with other devices to form a computer network.

6. Lesson 1—Networking BASICS6 Purpose of a Computer Network Summarized in a single word: sharing. Individual computers are isolated. Networked computers can share resources. Three types of resources can be shared. Networks also make computer management easier.

7. Lesson 1—Networking BASICS7 Share Software and Data Application and utility software can be shared by all users across the network. This requires only a single software copy to be purchased and maintained. Data files can also be shared. This makes data more accessible and maintains integrity.

8. Lesson 1—Networking BASICS8 Share Hardware Sharing is an essential feature of a computer network. This reduces costs and the work of support staff. Printers, fax modems, scanners, hard drives, CD-ROMs, and DVDs can all be shared.

9. Lesson 1—Networking BASICS9 Improve Communications Communication is essential in today’s businesses. Computer networks can help in improved communications through groupware. E-mail, electronic calendars, collaborative writing, and video conferencing are available.

10. Lesson 1—Networking BASICS10 Centralize Management Support staffs are stretched to the limits. Computer networks allow computers to be managed from one central location. Software updates can be “pushed” to users’ computers. Problems can be diagnosed over the network. Training can be done over the network.

11. Lesson 1—Networking BASICS11 Network Communications Source Message Channel Receiver Noise Feedback Context

12. Lesson 1—Networking BASICS12 Network Communications

13. Lesson 1—Networking BASICS13 Types of Networks Two types of network classifications  Classified by device that controls network  Classified by distance between devices

14. Lesson 1—Networking BASICS14 Types of Networks

15. Lesson 1—Networking BASICS15 Peer-to-Peer Network No single computer controls the network. Each computer is the same (a peer) to all others. It is suitable for small offices.

16. Lesson 1—Networking BASICS16 Server-Based Network The network is controlled by a special high-powered server. The server is dedicated to running the network. Print and file servers, application servers, communication servers, and directory service servers are common.

17. Lesson 1—Networking BASICS17 Server-Based Network

18. Lesson 1—Networking BASICS18 Local Area Network Network computers are located relatively close to each other. They are generally limited to buildings owned by one organization. They operate at high speeds. They are low-cost networks.

19. Lesson 1—Networking BASICS19 Local Area Network

20. Lesson 1—Networking BASICS20 Wide Area Network Network computers are spread out over a larger area. They generally cross public thoroughfares. They are often managed by public carriers. They operate at lower speeds. They are a higher-cost network.

21. Lesson 1—Networking BASICS21 Wide Area Network

22. Lesson 1—Networking BASICS22 Summary A computer network is defined as multiple computers and devices that are all connected together. By connecting the computers together, the capabilities of each computer are increased so the users can accomplish more. The purpose of a computer network is to share. Application software, utility software, and the data that serves as input into the software can all be shared across a network. Computer hardware can also be shared on a computer network. Printers, fax machines, scanners, modems, hard disk drives, CD-ROM drives, and DVD drives are just a few of the hardware devices that can be shared across a computer network.

23. Lesson 1—Networking BASICS23 Summary (continued) Computer networks can be important tools that help improve communication between users. A special category of software that assists with communication over a computer network is known as groupware. Groupware refers to programs that help people work together collectively even if they are located remotely from each other. One of the most common groupware applications used across computer networks is electronic mail, or e-mail. Groupware services also include electronic calendars, collaborative writing software, and video conferencing. The communication that takes place between devices on a computer network is known as telecommunications. Telecom- munications is defined as transmitting information over a distance and is generally considered to be a two-way transmission of voice, video, or data.

24. Lesson 1—Networking BASICS24 Summary (continued) Computer networks allow the computers connected to the network to be managed from one central location. Software updates can be “pushed” across the network to all computers, thus eliminating the need for support staff to visit every office and perform the new installation. Problem diagnosis can be performed across the network. Centralized management can be used for training as well. Computer networks are generally classified two different ways. The first classification of networks involves the device that actu- ally controls the network. In a peer-to-peer network, no single high-powered computer controls and manages the network. The computers collectively run the network instead of a special dedicated computer doing it. These networks are suitable for small offices that need to share a printer or computer data.

25. Lesson 1—Networking BASICS25 Summary (continued) The second type of network classified by the device that con- trols the network is known as a server-based network. Unlike a peer-to-peer network, a server-based computer network is con- trolled by at least one special high-powered computer. These special computers are called servers, while the individual com- puters on the network are called clients. Servers are usually dedicated to running the network and do not function as clients. Instead, their sole job is to service requests quickly from the network clients and ensure the security of the software and hardware. There are many different types of specialized servers.

26. Lesson 1—Networking BASICS26 Summary (continued) Networks can also be classified by geography or how close the devices are to each other. There are two categories of networks based on geography. The first is a local area network (LAN). A LAN is a computer network that has all the computers relatively close to each other. They operate at high speeds for a low cost. A wide area network (WAN) transmits over a public thorough- fare, such as a road, highway, railroad, or body of water. A WAN service must be purchased from a carrier. WANs are managed by the carrier instead of by the user. Compared to LANs, the cost of WANs is high and they operate at a low speed.