HTML (English) 01
What is HTML?
How are web pages created? Like computer programs, Web pages are created by use of a computer language. Thus is a particularly simple language known as Hypertext markup Language (HTML).
An HTML program is a simple text file. It doesn’t have to be compiled or processed through a special interpreter. This makes it an easy language to learn. An HTML program includes a series of tags that are placed within the text that will appear on the title, another block should be displayed in a boldface font, and so forth. These tags are similar in purpose the special symbols that printers used to mark up a document for printing before the advent of electronic publishing.
Once a web page is created, it is stored on a computer that is constantly connected to the Internet. This computer continuously runs a special program, called a web server that waits until a user running a web browser requests access to a page. When the web server sees someone ask for a particular page, it jumps into action and sends the page over the Internet to the browser. When the browser sees the HTML tags inside the document, it uses them as instructions on how to format the document; it uses them as instructions on how to format the document for display to the user.
Looking into HTML
Most of the tags used in HTML specify the structure of a Web page, not it’s exact appearance. In an HTML program, you might say, “I want the title of this page to be ‘Aussie Lanka IT Corporation,” but you can’t give the browser instructions that say, “Display the title in mauve type in the lower right-hand corner.” Now, if you really have a hankering for mauve, you might find this limiting. Remember though, that the Web protocol allows people the world over to view your page-on all sorts of equipment. Each computer system has a different convention for displaying a title. So, by only specifying the structure of your document and not its appearance, you ensure that the Macintosh people will see the title where they expect it, as will the UNIX and Windows 95 folks. The browser itself decides exactly how a given tag should affect the appearance of a page. For example, there is a tag that defines a given block of text within a document as a top-level heading. The precise font that will be used and the size of the font are selected by the browser, not by the author of the page.
Although this makes the creation of Web pages much easier than it might otherwise be, it places a tremendous responsibility on the browser, because the browser determines the actual layout of the document. This means that no two browsers will display your pages quite the same. Two people using different browsers (or different versions of the same browser) may view the same web page and come away with very different opinions of the visual quality of the page. One user may see a page with good layout, where the various components fit together nicely on the screen. Another might see a jumbled mess, where things just don’t seem to fit right. Even the colors may look wrong, making it difficult to read the text because the background color and the text color are too similar.
This kind of mix-up usually occurs when the person who designed the page assumed that everyone in the world would be using the same video card and monitor. Additionally, if the designer of the page has used nonstandard tags supported only by a particular browser, it’s likely that the page will appear broken under another browser or on a different machine.
Today the most popular browsers are Netscape navigator and Microsoft Internet Explorer. Each is quite sophisticated and, as you’ll see later, fully capable of running Java programs. Which browser you use is up to you, though web page designers tend to use both. By avoiding the use of browser-specific tags and by checking your Web page design efforts using both Navigator and Internet Explorer, you can ensure that most web users will find your pages pleasing to the eye.
