Meet the Internet
The 'internet' has many parts. When most people talk of 'the internet' they are in fact referring to only one part of it - the World Wide Web. Yet e-mail (for example) is a very important part of the internet, yet many people use a separate program for their email. So what are the different parts of the internet, and how do they all fit together?
One of the earliest bits of the Net is FTP, which stands for File Transfer Protocol. 'File' and 'transfer' are easy enough to understand, but what is a 'protocol'? Put simply, a protocol is a method that two computers have agreed to use when they are talking to each other. The very first job of the internet was to move files from one computer to another even when these computers were very far apart, and File Transfer Protocol did this job. If you use the Net just to browse your favourite websites, you may not use FTP a lot, but the people who built those websites almost certainly used a FTP program to put the pages on the web in the first place.
We all know what e-mail is, but did you know that you usually use two different protocols with it? We usually send mail by SMTP (Simple Mail Transfer Protocol) and pick it up, as you might expect, by POP (Post Office Protocol). And yes, the World Wide Web also uses a protocol. The links on a web page that you click to take you to another part of the Net are called 'hypertext links'. Look at the top of your web page, and you should see that you are at "https://www.english-online.org.uk/" . Http stands for (you guessed it!) HyperText Transfer Protocol, and the 'www' after that shows that this page is part of the World Wide Web.
Today, if we just want to browse the web, we can do almost everything with one program - a web browser. A browser is one kind of 'net interface'. Net interfaces are programs which sit between you and the internet and help you and the Net make sense to each other. The browser takes care of the technical details of connecting you to the web, and makes sure that the information from the internet arrives in a way that makes sense to you. It also finds out what you want to do, and passes on the information in a way that the internet can understand.
Websites are built in different ways. Pages that contain a lot of information but are not very interactive are called 'static' pages. These are usually written in a language called HTML (HyperText Markup Language). Interactive pages can be written as if they are computer programs. Because it can be dangerous to run unknown programs, many interactive websites today use interactive scripts that don't run on your computer. These scripts often use a language developed for Personal Home Pages (php)
Sometimes, you might want to get sound or video from the internet. These are things that the internet can only deliver to you through File Transfer Protocol, but you see them in your browser because your browser has special programs called 'plug-ins' which run these files as soon as they arrive.