What is a web page?

 

In this section, you're going to learn just what a web page is and how it can be read by a browser like Internet Explorer or Firefox. You'll also construct your very first web page. Let's make a start.

Files on your computer come with extensions. If you wrote a letter using Microsoft Word and saved it with the name 'MyLetter', the software would add four letters to the file name (three in older versions). Because it was typed using Word, the four letters that get added to your filename are .docx. So your file name will be 'MyLetter.docx' and not just 'MyLetter'. If you created a spreadsheet in Microsoft Excel and called it 'Accounts' the Excel software will add its own four letter extension to your file name. It will add .xlsx. So you file name will be 'Accounts.xlsx' and not just 'Accounts'. So you get a different four letter extension depending on the software you used.

These extensions are very important to computers. They are used to identify the type of file it is. With a file extension, Word can recognise its own documents. It sees the letters docx and says 'Ah yes, that's one of mine. I can open it.' If it sees a different extension, xlsx for example, it says 'What the heck is that?' You may then get an error message telling you that the file type is not recognised.

Web pages have their own file extensions. Oddly there are two different extensions, a three letter file extension and a four letter extension. Web pages come with the extension .htm or .html. A browser can recognise either extension.

When you open up a web page with your browser, Internet Explorer for example, the browser software checks the file extension, the same check that Word and Excel make. If it sees the .htm or .html extension it knows it's a web page and then tries to open it. (Modern browsers, though, can open up other types of files. Internet Explorer can open up your Word documents and PDF files.)

Behind the scenes, however, the thing that Internet Explorer is trying to open is really a text file that has had its extension changed from .txt to .htm. The text file though will have special symbols and words, called Tags. When the browser sees these Tags it goes to work, displaying whatever you typed and hiding the Tags from your viewers.

Most web pages on the internet are written in code called HTML. HTML stands for HyperText Markup Language, and is fairly easy to get the hang of. That's because HTML is not a programming language: it is a language designed to improve the presentation of text. For example, in Microsoft Word, if you want a nice big heading, you can select a font size from a menu. HTML has an easy way to change the size of text of headings, too, which you'll see in a moment. But that's basically all you are doing with HTML ' presenting text and images on a page. The way you do this is with things called TAGS.

 

What is HTML 5?

HTML comes in different versions. When people talk about HTML 5 they are talking about the updates to the mark up language. These updates were agreed (mostly) by a whole host of different parties, all members of an organisation called W3C. W3C was founded in 1994 by Tim Berners-Lee, who also created the first version of HTML and invented the World Wide Web. They now oversee the defining of new Web technologies. Comapnies who make browser like Microsoft (Internet Explorer), Mozilla (FireFox), and Apple (Safari) can then decide which of the new Web technoligies they wish to implement.

Most of the big names in browser technology decided to implement quite a lot of the new suggested updates (specifications) put forward by the W3C. These specifications are commonly known as HTML 5. In practice, this means implementing features like HTML Video and audio directly into the browser, as opposed to needing a 3rd party plugin like Adobe's Flash. Another exciting update is something called the Canvas tag. This allows you to create quite sophisticated animations and graphics using Javascipt, again without needing a 3rd-party plugin.

There are a whole lot of new HTML tags that take browser technology forward into the 21st century. Throughout this course, we'll introduce you to the essential HTML 5 tags that you need in order to create a modern web page.