New Technologies and What They Mean To You: Part 1 - HTML (Page 2 of 5 )
Definition (with help from dictionary.com) A markup language used to structure text and multimedia documents and to set up hypertext links between documents, used extensively on the World Wide Web. A set of tags and rules (conforming to SGML) for using them in developing hypertext documents. "Tags" are embedded in the text. A tag consists of a "<", a "directive" (case insensitive), zero or more parameters and a ">". Matched pairs of directives, like "<TITLE>" and "</TITLE>" are used to delimit text which is to appear in a special place or style.
Where "A" and "/A" delimit an "anchor", "HREF" introduces a hypertext reference, which is most often a Uniform Resource Locator (URL) (the string in double quotes in the example above). The link will be represented in the browser by the text "foo" (typically shown underlined and in a different colour).
A certain place within an HTML document can be marked with a named anchor, e.g.:
The "fragment identifier", "baz", can be used in an HREF by appending "#baz" to the document name.
Other common tags include <P> for a new paragraph, <B>..</B> for bold text, <UL> for an unnumbered list, <PRE> for preformated text, <H1>, <H2> .. <H6> for headings.
HTML supports some standard SGML national characters and other non-ASCII characters through special escape sequences, e.g. "é" for a lower case 'e' with an acute accent. You can sometimes get away without the terminating semicolon but it's bad style.
The World-Wide Web Consortium (W3C) (www.w3c.org) is the international standards body for HTML.
Latest version: XHTML 1.0 (http://www.dictionary.com/search?q=XHTML), as of 2000-09-10.
W3C HTML Home (http://www.w3.org/MarkUp/).
Character escape sequences (http://www.w3.org/hypertext/WWW/MarkUp/ISOlat1.html).
What It Really Is HTML is the base language of the Internet. For a web page to be displayed at all in the browser HTML must be used as it is the source of information, design, layout, etc. Every other language whether it is server-side like ASP and PHP or a complete development suite such as .NET or J2EE requires HTML as it's final output.
HTML is one of the simplest languages to learn mainly because it isn't a programming language, it functions on the simple principle of:
Advantages HTML is very good at what it was designed for: The display and linking of different kinds of information. HTML was created so that any document created in HTML could be viewed in any application which understood HTML (a relatively simple task).
Because it was created on the Standard Generalized Markup Language standard, HTML is very easy to learn, I've taught it to college and high-school students in a period of three hours of class time, and taught it to hundreds of friends and colleagues based upon the simple principle of "tag, property=value" as the rest can be picked up from a reference manual.
Disadvantages HTML has been abused since it's roots. It is now used for hundreds of stylistic elements which should never have been part of HTML. Now HTML is more about "the web page" then about the clear and concise distinction between design, logic and content which is why other technologies such as PHP & ASP and XML were created.
Examples If you wanted to see examples of HTML you could go to any web page and simple View Source (often contained in the menu when you right click on the web page). Here are some standard types of things you might find:
A paragraphs of text:
<p>Hello, this is my first paragraph.</p>
Linking to another web page:
<a href="page2.html">Go to Page 2</a>
Linking to another web site:
<a href=http://www.mysite.com>Go to MySite.COm</a>
Linking to an "anchor" on the current page:
<a href="#author">View Author</a>
Using all 3 together:
<a href=http://www.mysite.com/page2.html#author>View Author on Page 2 of MySite.Com</a>
<font face="arial" color="#FF0000" size="2"><b>Some bold, red text in Arial</b></font>
Similar Technologies There are many technologies which are very similar to HTML in terms of how they look in code, mainly because there are many technologies which are based upon the SGML standard. Some of these include:
XML: XML allows you to structure data and then share that data across any system which can read XML. It ensures that the data is completely separate from the design of a page.
SVG: Based upon XML, SVG is a tag-oriented approach to describing vector graphics. Though it is currently very young, SVG does have much potential for dynamic images through code.