Web Standards

I want to know about web standards that one has to follow while developing web pages. An idea on this by any one is appreciated.

The World Wide Web Consortium (W3C), along with other groups and standards bodies, has established technologies for creating and interpreting web-based content. These technologies, which are called, web standards. These are carefully designed to deliver the greatest benefits to the greatest number of web users while ensuring the long-term viability of any document published on the Web