...the affordances of the environment are what it offers the animal, what it provides or furnishes, either for good or ill." "I mean by affordance something that refers both to the environment and the animal It implies the complementarity of the animal and the environment.
Thus, for Gibson, it is the relation between(a) the shape of an object and(b) the shape plus degrees of freedom of the joints in my hand that affords me the opportunity to grasp this object, no matter whether I can see the object or not; the affordance is out there. Norman departs from Gibson in that affordances become perceived and culturally dependent. Norman's affordances also apply to technologies and media"
...affordance refers to the perceived and actual properties of the thing, primary those fundamental properties that determine just how the thing could possibly be used. Affordances provide strong clues to the operations of things. Plates are for pushing. Slots are for inserting things into no picture, label or instruction[to the user] is required." Affordances also apply for technologies. Different technologies afford different operations. they make some things easy to do, others difficult or impossible.