What is the Internet? - An introduction

The Internet is a vast network of millions of computers straddling the world. It is open for anyone to join. There are over 100 million users throughout the world with the biggest concentrations in the US and Canada; followed by Japan, Germany and the UK.

The Internet supports a number of services. The most important ones are the World Wide Web (WWW) and Electronic Mail (Email), followed by the File Transfer Protocol (FTP) and Usenet (newsgroups / discussion groups).

This page introduces each of these services. You can click on the links for more detail.

The World Wide Web

The World Wide Web is the service that has made it easy and fun to access information on the Internet. Information can be presented in an attractive and accessible form. It is stored in pages that are a mixture of text and pictures and can contain sound, video and animations. Navigation is made easy by links to related information, which are embedded in the pages at the most appropriate point. When you position your mouse pointer over a link and click the mouse button, you automatically link to the other information whether it be on the same page, a different page on the same computer or any page on any other computer on the World Wide Web. You do not have to worry about what type of computer the page is stored on or where it is in the world – this is all taken care of automatically. The words at the start of the next sentence are an example of a link or hyperlink. This link takes you to a page that tells you more about hyperlinks.

A major problem with the Internet is finding the information you want from amongst the millions of pages at your disposal. Directories and search engines are designed to address this problem. Directories, such as Yahoo, organise sites into categories such as "Chemical Companies in the UK", "Football teams", etc. For each category a list of links to relevant sites is provided. Search engines scour the Web building up huge indexes of pages with associated key words. You can then type in the key words that you are interested in such as " Chemical Engineering" or "Spice Girls" and you are provided with a list of links to those pages that match your key words.

In order to use the World Wide Web you need to have a machine with a piece of software called a Browser on it. You also need a mechanism for connecting to the Internet - this will involve a modem unless you are on a Local Area Network that is already connected to the internet. The Browser is the window into the World Wide Web. It retrieves and displays Web pages on your screen. With the importance of the Web it is fast becoming an essential part of every computer’s desktop. The two main browsers provided by Netscape and Microsoft are used by over 80% of Web users.

The World Wide Web is used to publish all types of information. Web pages are grouped into Web Sites which provide information about a particular subject matter, an individual or an organisation. All the major corporations of the world have Web sites. Most company web sites focus on providing information about the company but an increasing number are highly profitable either as a sales outlet or through offering a cost effective service.

The Web pages are ordinary text files that use a language called HTML (HyperText Markup Language) to control the appearance of the page and to embed objects such as pictures or links (to other pages). Coding HTML is straightforward but tedious. Many editors (such Netscape Composer and Microsoft FrontPage) are now available to provide a word processor type interface so that it is not necessary to learn HTML in order to produce Web Pages. Indeed straightforward web pages can be created by the popular Word Processors such as Microsoft Word.

Internet Email

Users of the Internet can send electronic messages to each other. These messages are known as electronic mail or Email. Messages are stored in a mailbox on the Internet for the mail recipient to obtain when he or she is next connected to the Internet. All the major Email systems have gateways into Internet mail. Thus for example, it can be possible for an employee in a company that uses Lotus Notes to communicate via the Internet, with an employee of another company that uses Microsoft Exchange.

File Transfer Protocol (FTP)

File Transfer Protocol is a mechanism for moving files between two machines over the Internet. It is invariably referred to as FTP. An FTP site is a collection of documents, software, etc. which Internet users can transfer to their computers using FTP. The term anonymous ftp is used to refer to sites where the user can access files without having to identify themselves, they are not asked to provide a user id and password. FTP is also commonly used to transfer Web pages from the Webmaster's machine that holds the Web Site.

Usenet Newsgroups - also known as Discussion Groups

Usenet provides an opportunity for Internet users to use electronic mail, to hold discussions with others who share a common interest. There are over 30,000 newsgroups covering every conceivable area of interest, ranging from atomic science to Star Trek. They work by users sending email to the appropriate newsgroup where it is stored along with the email form other contributors to that newsgroup. Other Internet users can go to the Newsgroup and read all the recent email. They in turn can then send a message to the group (for all to see) or directly to any individual who had sent a message to the group.