| Every web designer is familiar with the HTML | | | | Language) is the basis for HTML. XML is a more |
| programming language, which stands for Hypertext | | | | refined subset of SGML, and forms the basis for |
| Markup Language. The language has been in use since | | | | XHTML. On the whole, XHTML is more flexible than |
| the advent of cyberspace, and although it will | | | | HTML. |
| probably always be used, it is already being | | | | XHTML was developed for two reasons: (1) to try to |
| supplemented by newer, more versatile versions of | | | | create a language that could more effectively |
| HTML. | | | | convey the meaning of a particular webpage to a |
| The Extensible HyperText Markup Language | | | | computer, and (2) to create a layout for webpages |
| (XHTML) is a family of current and future document | | | | that would be universally understood by browsers |
| types and modules that reproduce, subset, and | | | | running on different platforms or on different types |
| extend HTML, reformulated in XML. XHTML family | | | | of screens. |
| document types are all XML-based, and ultimately are | | | | This is extremely important, because people are now |
| designed to work in conjunction with XML-based user | | | | using a wide variety of gadgets to connect to the |
| agents. | | | | internet, as almost every electronic device on the |
| Unlike HTML, which focuses on describing how data | | | | market now comes equipped with email and internet |
| or text is supposed to be displayed, The XML | | | | access. Cell phones, palm tops, computers installed in |
| language instead describes what the data is. So, XML | | | | automobiles; they all have built-in web access. |
| is not something that is apparent on a web page, | | | | Each of these devices display text and graphics |
| because it does not actually tell your browser how to | | | | differently, and utilize different platforms and a |
| display the data. As information and data presented | | | | variety of web browsers. As a result, someone using |
| on the world wide web became more complex, XML | | | | a cell phone to access a certain web site may not be |
| was invented to effectively structure, store, and | | | | able to view it properly because the browser running |
| send this information. | | | | on that cell phone might not be able to display the |
| What makes XML truly unique is that there are no | | | | HTML. The platforms that run on some of these new |
| predefined tags as is the case with HTML. All of the | | | | products and devices are not totally compatible with |
| tags used in HTML have already been defined, such | | | | HTML. |
| as the paragraph tag, the header tag, and all the | | | | So, it is imperative that most web designers learn to |
| various style tags. XML is not defined. You can make | | | | design web pages in XHTML. As almost every |
| your own tags! | | | | electronic device on the market is now equipped with |
| XML, forms the basis for a language called XHTML. | | | | internet access, it is important to use a versatile |
| XHTML is what is known as a meta-language, which | | | | programming language like XHTML so that your web |
| is a language for defining a markup language. To put | | | | pages can be viewed and properly formatted across |
| it simply, SGML (Standard Generalized Markup | | | | a wide variety of platforms. |