” An affordance is a property of an object, or an environment, which allows an individual to perform an action. For example, a knob affords twisting, and perhaps pushing, while a cord affords pulling.
Different definitions of the term have developed, as explained in the following sections. The original definition described all actions that are physically possible. This was later adapted to describe action possibilities of which an actor is aware. The term has further evolved for use in the context of human–computer interaction (HCI) to indicate the easy discoverability of possible actions.
The word is used in a variety of fields: perceptual psychology, cognitive psychology, environmental psychology, industrial design, human–computer interaction, interaction design, instructional design, science, technology and society (STS), and artificial intelligence.”