What is validation ?
According to the W3c, Validation is a process of checking your documents against a formal Standard, such as those published by the World Wide Web Consortium (W3C) for HTML and XML-derived Web document types, or by the WapForum for WML, etc. It serves a similar purpose to spell checking and proofreading for grammar and syntax, but is much more precise and reliable than any of those processes because it is dealing with precisely-specified machine languages, not with nebulously-defined human natural language.
Why taking the trouble to validate your XHTML ?
- Properly written XHTML code will render better, render on more browsers, and render faster than XHTML with errors. It’s also more easily adapted to print and alternative browsing devices like mobile phones and handheld computers.
- Properly written XHTML code is more likely to be “future-proof” (backward compatible with future standards and future web browsers).
- Browsers are becoming more standards compliant, and it is becoming increasingly necessary and important to write valid and standards compliant XHTML code
- Poorly written XHTML can greatly reduce the amount of traffic your web site receives from search engines.
- Write XHTML code right the first time and write it once.
- You don’t want to look foolish among your friends while not knowing the rules, uh?