1. W HAT IS A N ETWORK ? National 4/5 Computing Science

2. L ESSON AIMS By the end of this lesson you will be able to:  Describe what a network is  Describe what a stand alone machine is  Explain what a LAN and WAN is  Describe the difference between the internet and the World Wide Web

4. B ACK IN THE DAY … When I went to school the computer’s were not connected. We had to use the same computer every time

5. A NY ISSUES WITH STAND ALONE MACHINES ? What if ‘ your ’ computer fails Someone else is using your machine? You have 130 computers and need to install some software.

6. N ETWORKS A network is a series of computers that are connected so that they can send and receive data. The first information was sent between computers in 1969 between the University of California and Stanford University

7. T YPES OF NETWORKS Local Area Network (LAN) This is a network that connects computers in a small area/single building Can be wired or wireless Wide Area Network (WAN) This is a network that connects computers over large distances such as in different towns and countries. The internet is an example of a WAN. Are usually connected by telecoms links(phone wires/fibre optics) or satellites.

8. S AMPLE LAN

9. S AMPLE WAN

10. A DVANTAGES OF N ETWORKS They can be expensive to create so why bother with them? Why does the school have a LAN? 1. Networks make it easier to share data 2. Networks allow expensive peripherals such as printers and scanners to be shared 3. Can allow communication via email

11. Q UESTION How many of you have the internet at home? None of you have! You have access to the world wide web! More on this later…