What does validating a website mean
This will definitely help your website in the future.
Also, for the "img" element, width="really wide" is also accepted as valid.The W3C is the World Wide Web Consortium and provides guidelines based on best practice, regarding how websites and web pages should be structured and created for long–term durability.The W3C validation is just a standard for specified machine language, checking web documents, spelling, grammar, syntax, and proofreading.Mark-up validators cannot see the "big picture" on a web page, but they excel at picking up missed closing tags and other technicalities.DTD-based validators are also limited in their ability to check attribute values according to many specification documents.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 Wap Forum for WML, etc. W3C Non valid pages rely on the browser to auto-correct your code, and each browser does this differently.
So if you forget to close a tag, Firefox might ignore this but Safari doesn’t and you end up with a broken layout.
XHTML is the newest standard for this hybrid markup language designed for web documents.
It is a combination of classic HTML and advanced XML.
Shaun Anderson conducted an interesting validation test; Does Google like valid code? This experiment included 4 pages with the same content but a mixture of valid and non-valid HTML and CSS.
The result was that Google picked up the page that had valid HTML and valid CSS and indexed this page over the rest.
DTD-based validators are technically not able to test for these types of attribute value problems.