Identify Errors in website : As per W3C Valida tor Standards and sort out the same

W3C Standards are also called W3C Recommendation and it is the final stage of ratification process of the World Wide web consortium (W3C) working group concerning the standard. It signifies that a document has been subjected to a public and W3C member organizations review. It aims to standardize the web technology (ie. make the web accessible to all users despite difference in culture, education, ability, resources and physical limitations.

You can validate the site with the help of following resources.

To validate the single page :

http://validator.w3.org/

To validate the entire site :

http://htmlhelp.com/tools/validator/