W3C Compliant is a World Wide Web Consortium and they have generally helped to create guidelines for website creators to follow. Whilst you do not have to follow the guidelines, it does help if you do because they are there to help your site to appeal to more people. Basically you can design your site any way you like, however you have to bear in mind that not everybody will have the same browser as you and the pages you design may not load up on some people's computers and if you are a business that could lose you potential clients. The W3C Compliant is there to help your site be disabled friendly and to appeal to everybody regardless of their browser or resolution speeds etc.
So whilst you can design your own website however you like, it is always better to stick to the W3C Compliant and that way you will ensure that your site is accessible to almost everybody.
So whilst you can design your own website however you like, it is always better to stick to the W3C Compliant and that way you will ensure that your site is accessible to almost everybody.