What is WCAG 2.0?
WCAG 2.0 meaning The Web Content Accessibility Guidelines (WCAG) 2.0 is focused on providing an international technical standard for web content. It has 12 guidelines that are organized under four principles: perceivable, operable, understandable, and robust. The guidelines each have a testable success criteria, which are at three levels: A, AA, and AAA.
reference: Usability.gov – Glossary