W3C, and how it benefits web developers.

The World Wide Web Consortium (W3C) was founded by creator of the internet Tim Berners-Lee, it is a document reviewed by many parties who all have the common goal of making the Internet easily accessible to everyone.
The Web Content Accessibility Guidelines are a group of recommendations developed by the W3C and other parties too better help website developers create websites that are more accessible to people mainly with disabilities such as blindness. Websites are graded against the guidelines to see wheher they conform to them and thus offer better access to the public.
So basically, the W3C is looking out for less priviledged people by helping make websites more open and interactive with everyone.