What are the four major categories of accessibility?

Question

The four main principles of the web content accessibility guidelines are Perceivable, Operable, Understandable and Robust. On Sept 13, 2019:

Hagrid P Hazard · Accepted Answer

The four main principles of the web content accessibility guidelines are Perceivable, Operable, Understandable and Robust. On Sept 13, 2019: