What is W3C validation?

[grofee]

W3C validation is the free service which helps in checking out the validity of the web documents. These are the services that allows internet users to check the HTML and XHTML documents for well formed markups. In this, the user will get the surety of their website that whether it is up to the coding standard which is setup by world wide web consortium or not.

[Akshay_M]

W3C validation is the process of checking a website's code to determine if it follows the formatting standards. If you fail to validate your website's pages based on W3C standards, your website will most likely suffer from errors or poor traffic owing to poor formatting and readability.