HTML is a computer language devised to allow website creation. These websites can then be viewed by anyone else connected to the Internet. It is relatively easy to learn, with the basics being accessible to most people in one sitting; and quite powerful in what it allows you to create. It is constantly undergoing revision and evolution to meet the demands and requirements of the growing Internet audience under the direction of the organisation charged with designing and maintaining the language.
The definition of HTML is HyperText Markup Language.
HyperText is the method by which you move around on the web — by clicking on special text called hyperlinks which bring you to the next page. The fact that it is hyper just means it is not linear — i.e. you can go to any place on the Internet whenever you want by clicking on links — there is no set order to do things in.
Markup is what HTML tags do to the text inside them. They mark it as a certain type of text (italicisedtext, for example).
HTML is a Language, as it has code-words and syntax like any other language.
How does it work?
HTML consists of a series of short codes typed into a text-file by the site author — these are the tags. The text is then saved as a html file, and viewed through a browser, like Internet Explorer or Netscape Navigator. This browser reads the file and translates the text into a visible form, hopefully rendering the page as the author had intended. Writing your own HTML entails using tags correctly to create your vision. You can use anything from a rudimentary text-editor to a powerful graphical editor to create HTML pages.
What is CSS?
Cascading Style Sheets (CSS) is a language for specifying how documents are presented to users.
A document is a collection of information that is structured using a markup language.
Presenting a document to a user means converting it into a usable form for your audience. Browsers, like Firefox, Chrome or Internet Explorer, are designed to present documents visually, for example, on a computer screen, projector or printer.
Examples
A web page like the one you are reading is a document.
The information that you see in a web page is usually structured using the markup language HTML (HyperText Markup Language).
Dialogs in an application, also called modal windows, are often documents.
Such dialogs may also be structured using a markup language, like XUL (XML User Interface Language), which you will find in some Mozilla applications.
Why use CSS?
Use CSS to define styles for your documents, including the design, layout and variations in display for different devices and screen sizes. You can place your CSS in the head of a document with an embedded style sheet, or attach a separate file that defines your styles with an external style sheet. To link an external style sheet to your document, you'll simply add a link to the style sheet in the "head" of the document.
An external style sheet has many advantages. Keeping the styles separate from your HTML content:
Helps avoid duplication
Makes maintenance easier
Allows you to make a site-wide change in one place
Example
Using CSS, you store the style information in common files that all the pages share. For example, when the documents link to the same style sheet that defines the color of h2 headers, you can apply the style for h2 header tags globally by changing one css attribute.
When a user displays a web page, the user's browser loads the style information along with the content of the page.
When a user prints a web page, you can provide different style information that makes the printed page easy to read.
How do HTML and CSS work together? In general, you use HTML to describe the content of the document, not its style. You use CSS to specify the document's style, not its content. Later in this tutorial, you will see some exceptions to this arrangement.
What Exactly Is JavaScript?
JavaScript is a programming language used to make web pages interactive. It runs on your visitor's computer and doesn't require constant downloads from your website. JavaScript is often used to create polls and quizzes.
What Do I Need to Run JavaScript?:
JavaScript support is built right into all the major web browsers, including Internet Explorer, Firefox and Safari. Provided that the visitors to your site are using web browsers that support JavaScript (most do) and have JavaScript enabled (it is by default), then your JavaScript will run when they visit the page.
What Is PHP?
Self-referentially short for PHP: Hypertext Preprocessor, an open source, server-side, HTML embedded scripting language used to create dynamic Web pages.
In an HTML document, PHP script (similar syntax to that of Perl or C ) is enclosed within special PHP tags. Because PHP is embedded within tags, the author can jump between HTML and PHP (similar to ASP and Cold Fusion) instead of having to rely on heavy amounts of code to output HTML. And, because PHP is executed on the server, the client cannot view the PHP code.
PHP can perform any task that any CGI program can do, but its strength lies in its compatibility with many types of databases. Also, PHP can talk across networks using IMAP, SNMP, NNTP, POP3, or HTTP.
