The World Wide Web and the Internet
Introduction
The Internet is part of many people's lives across the globe now. It is used for socialising, education, business, news reporting and so on. It has so many uses that it is difficult now to imagine life without it.
What is the Internet?
The Internet is a set of networks, both Local Area Networks (LANs) and Wide Area Networks (WANs) which are connected together usually using telecommunications facilities. These include the phone lines but also such communication technologies as satellite.
The Internet allows everyone to communicate quickly and allows the transfer of files and data between computers. Data (an email, a file or a web site, for example) starts at one computer. It is broken down into digital 'packets' of information. Each packet is then passed through other computers, with each packet often going by a completely different route to the other packets. When all the packets reach the final destination, they are reassembled into the original communication and can then be read.
World Wide Web
The World Wide Web (WWW) is often used interchangeably with the 'Internet' but it does have a different meaning. The WWW is a collection (a very large collection) of information held on the Internet in multimedia form. This includes text, pictures, video, sound and animations.
Web pages and web sites
The information on the Internet is stored in 'web pages' and the web pages are themselves stored at places known as 'web sites'. Web pages can be very large so you often need to scroll down to be able to read them. A set of web pages on one web site can be very large so they are usually broken down into different web pages and linked together using 'hyperlinks', which are also known as 'hotlinks'. These can also be used to link to other completely different web sites. Because any individual web site can be large, it usually has a 'home page'. This is usually the starting point for any web site and helps the user quickly find their way around and navigate through the rest of the web site.
Browsers
A 'web browser' is a type of application, which has been written by an individual or organisation to allow a user to get back and display multimedia information on the Internet. It can be used to surf the WWW as well as to provide other facilities, such as transferring individual files. Web pages sent over the Internet use a communications protocol known as http. This isn't secure so that if anyone intercepts these pages, they can view them. You can send and receive encrypted web pages over the Internet using the communications protocol known as https. This is important if you are sending or receiving sensitive information e.g. logging into your bank account. Browsers typically have a range of features, such as navigation tools, to move forward and backwards between web pages, facilities to save web pages or print them out and security features, for example, the facility to block certain web sites or block certain types of file. Examples of Browsers include Firefox , Chrome, Sahara and Explorer but there are many many others. Try doing a Google search for web browsers and download and try out some of the less known ones at home.
Intranet
One word you may come across from time to time is 'Intranet'. An Intranet is very similar to the Internet, except that it exists purely within a company or other organisation. A company's Intranet is only accessible by authorised users, usually by using a system of logins, passwords and access rights (as opposed to the Internet, which anyone who has a connection can access). It allows a company to distribute information only to its own employees, information that it might not want its competitors to have, for example.
Extranet
Sometimes, an Intranet will allow part of itself to be viewed by the public from the Internet. This means that part of a company's Intranet could be used to advertise itself. If a part of an Intranet is accessible via the Internet then this part is sometimes called an 'extranet'.