Computersight -

This is the memo you wanted about LAN, WAN, Internet and Intranet.

LAN (Local Area Networks)- A LAN is two or more computers connected by a cable. These computers can be in several buildings and communicate with each other.

There are lots of advantages and only few disadvantages.

Advantages of LAN computers are:

• Resources such as printers, scanners and other hardware can be shared, cutting down on hardware costs.
• Data can be shared, allowing all users access to data and the ability to update data.
• Software programs can be shared.
• Users do not need disks.
• Users can access their own work from any computer but no one else can access their work.
• All users can access and use the same software at the same time.

Disadvantages of LAN computers are:

• Hardware cost and installation cost may be high at first.
• As more users are on the network, the system performance may slow down.
• If the cable fails all the computers will be affected.

WAN (Wide Area Networks)- A WAN network is where computers are linked over a wide area network this can be nationwide and even worldwide. There are two types of WAN, public and private. The Internet is an example of a public WAN, private WANs use privately rented lines. WANs need one or more host computers. There are low speed links and high-speed data services such as the Integrated Services Digital Network (ISDN), which carries voice, data, images and video via a single digital line.

Internet- The Internet is an international network of computers. The Internet is a very big Wide Area Network (WAN). A PC connected to a normal telephone line connects it all. The PC is connected with something called a modem, which changes the computers digital signals into analogue signals carried of the telephone line and vice-versa. Your modem is owned by your Internet service provider (ISP). These ISP’s have computers, which are always connected to the Internet. All the information sent from your PC goes through the ISP.

Intranet- The intranet is like a mini Internet to organisations. It can be used to produce documents etc. and then they can be made accessible to the other staff on the intranet. Any documents for the people outside of the organisation can be put onto a website and available for them to download it.