ARIA

Discrete user interface object with which the user can interact.

Any software that retrieves, renders and facilitates end user interaction with Web content.

Presentable to users in ways they can construct an appropriate meaning.

A hierarchical definition of how the characteristics of various classes relate to each other, in which classes inherit the properties of superclasses in the hierarchy.

A state is a dynamic property expressing characteristics of an object that may change in response to user action or automated processes.

Main indicator of type. 

A connection between two distinct things. Relationships may be of various types to indicate which object labels another, controls another, etc.

Attributes that are essential to the nature of a given object, or that represent a data value associated with the object.

Presentable to users in ways they can sense. 

Any DOM descendant of the element, any element specified as a child via aria-owns, or any DOM descendant of the owned child.

Usable by users in ways they can control.

A description of the characteristics of classes and how they relate to each other.

In the context of user interfaces, an item in the perceptual user experience, represented in markup languages by one or more elements, and rendered by user agents.

Required for conformance. By contrast, content identified as informative or "non-normative" is not required for conformance.

The Nemeth Braille Code for Mathematics is a braille code for encoding mathematical and scientific notation.