Computer Networks

Computer Networks What a network is: A computer network is developed by linking computer systems together. The network includes the computer systems, the connections and the hardware needed to allow the communication. Networks can be limited to a building/area (a Local Area Network or LAN) or worldwide such as the Internet (a Wide Area Network or WAN) The advantages of networking:

• • • •

Computers can communicate with each other and share data and files. Computing power and/or storage facilities can be shared. Hardware such as printers can be shared. There is control over which programs and settings a user has access to.

The disadvantages of networking:

•

A virus can spread more easily. If a virus gets into one computer, it is likely to spread quickly across the network because they are linked.

•

As data is shared there is a greater need for security. Users of the network have to have user ids and passwords.

•

If the server fails, all the workstations are affected. Work stored on shared hard disk drives will not be accessible and it will not be possible to use network printers either.

•

The cost of installing the equipment is greater. Cabling can be expensive to buy and to install.

•

Damage to cables can isolate computers. Some sections of the network can become isolated and will not be able to communicate with the rest of the network.

•

Because networks can be complicated to maintain, a network manager may be needed to run the system.

Common Network Environments: An intranet: An intranet is provides information on web pages but the information can only be accessed from the local network. Advantages:

• • • •

An Intranet is free because it does not involve phone links. Information can be easily updated and shared inside a company or school. The web pages can be viewed using a standard web page browser. More of the information will be useful because it was created for particular users.

Disadvantages: • Information cannot be shared outside the local network.

The Internet: The Internet is a world-wide network of linked computers sharing a vast amount of information. Advantages: • Millions of people contribute information. • Data can be rapidly added and updated to reach a huge audience. • It can be used to sell goods to a world-wide market. Disadvantages: • There is a lot of useless information, much of which is out of data and it can be very difficult to find what you want. • Much of the information is misleading or has not been checked for accuracy. • It is not regulated and offensive and illegal material exists. • Issues such as security become even more important as potential hackers could possibly be trying to break into a computer system from anywhere in the world

TASK From using your notes answer the following questions: -

1.

What do the terms LAN & WAN mean? LAN……………………………………………………………………. WAN……………………………………………………………………

2. How are computers connected together to form a LAN network?

3. In school we use a LAN network – how many printers do we need to have in each room?

4. When you log on to the computer your logon tells the computer who you are – what else will your logon tell the computer (think about your access on the computer)?

5. There are many disadvantages to using a LAN network – however we still choose to use it in school – Explain why you think this is?

6. What is the difference between an Intranet and the Internet?

7. Explain what you think is the biggest disadvantage of the Internet? Write your answer in full – giving an example.

8. What does the term “user id” mean in full?

9. What 3 things must you do to ensure the security of your data?

10. Imagine you have been asked to give a talk to the Year 7s about the problems of using the school network. One pupil asks you why they have to use passwords all the time. Explain to the pupil why we use passwords and what they should do to make sure they keep their password safe and secure. (read the notes for help)