interaction
Affordance
The possible actions an object's form suggests – a handle affords pulling; a raised, shadowed rectangle looks pressable.
Don Norman’s term (The Design of Everyday Things) for the relationship between a thing’s form and what you can do with it. In interfaces: does this element’s shape suggest its behaviour? Buttons that look pressable, inputs that look fillable, cards that look draggable.
The test that catches an enormous share of confusing interfaces runs both ways: does everything clickable look clickable – and does everything unclickable look unclickable? Text styled like a link that isn’t one breaks the same promise as a button that turns out to be decoration. See signifier for the companion idea: what’s possible versus what tells you it’s possible.