Accessibility is the practice of making your app or website usable for as many people as possible.
Most disabilities fall into one of the following four categories:
In the app development world, inaccessibility also includes people who don’t use mobile apps often or who use them with a slow or no internet connection.
An accessible user interface should be designed for color-blind users. An accessible designed app provides equal access to information and functionality for every user. This is independent of their physiological and technological conditions.
The WCAG are produced by the World Wide Web Consortium (W3C) and include a series of guidelines to improve web accessibility. The goal of the guideline is to provide "a single shared standard for web content accessibility that meets the needs of individuals, organizations, and governments internationally” (W3C). They include information like text, images and sound, but also code elements like structure or presentation.