Understanding Computer Networks and the Internet

Computer Networks

What is a Network?

A network is a number of computers linked together to allow the sharing of resources. A server usually provides services like file storage and email.

Types of Networks

There are two main types of networks:

• Local Area Network (LAN): A LAN covers a small area, such as a home or office.
• Wide Area Network (WAN): A WAN covers a large geographical area. Most WANs are made from several LANs connected together. WANs can be connected together using the internet.

Email

There are two main types of email:

• Client-based email: Often used by business users, client-based email involves downloading email from a server to an application on the user's computer.
• Webmail: Accessed through a web browser, webmail can be accessed from any computer with an internet connection.

The Internet and the World Wide Web

The Internet

The internet is a worldwide system of interconnected computer networks. When you connect your computer to the internet via your Internet Service Provider (ISP), you become part of the ISP's network.

The World Wide Web

The World Wide Web (WWW) is the part of the internet that you can access using a web browser, such as Internet Explorer or Firefox. It consists of a large number of web servers that host websites. Each website will normally consist of a number of web pages. A web page can contain text, images, video, animation, and sound.

Intranets

An intranet is a network that works like the internet but is only available within a particular organization, not to the public. An intranet may have web pages used to share company-specific data within that company, such as internal telephone numbers or details of employee benefits.

Connecting to the Internet

Requirements

To connect to the internet, the following are needed:

• A computer
• A telephone line (or other connection method)
• An ISP
• A web browser

Internet Service Providers (ISPs)

ISPs provide access to the internet. You need a web browser to view web pages. The most widely used are Internet Explorer and Firefox.

Connection Types

A connection made to the internet will be either analog or digital. Most people in the UK access the internet using broadband because it's much faster than other methods.

Benefits of Broadband

Broadband access allows feature-rich web pages to download quickly and allows users to quickly download large files. Faster internet connections also mean that the response time between clicking on a link and the new page appearing is reduced.

Things to Do on the Internet

Of the many things available to do on the internet, you can:

• Browse websites
• Send and receive email
• Download media files