WCAG is based on four main principles, often referred to by the acronym POUR:
Perceivable: Information and user interface components must be presented in ways that users can perceive. Operable: User interface components and navigation must be operable by all users. Understandable: Information and the operation of user interfaces must be understandable. Robust: Content must be robust enough to be interpreted by a wide variety of user agents, including assistive technologies.