Interaction Design
Designing the moment-to-moment behavior of an interface — how it responds to input, transitions between states, and gives feedback.
Interaction design (often shortened to IxD) is about behavior over time: what happens when you tap, drag, hover, submit, or wait. It defines states (default, loading, error, empty, success), transitions between them, and the micro-feedback that tells a user their action registered.
Good interaction design is mostly invisible — it removes doubt. When a button visibly reacts, a form explains its error inline, or a list animates a new item into place, that is interaction design making the product feel responsive and trustworthy.
Related terms
UI DesignThe craft of the visual and interactive surface of a product — layout, type, color, spacing, and components users see and touch.UX DesignThe practice of shaping how a product feels to use — its flows, structure, and logic — so people reach their goal with the least friction.Motion DesignThe use of animation and transitions in an interface to guide attention, explain change, and give a product a sense of life and quality.PrototypingBuilding an interactive, clickable model of a product so a flow can be experienced and tested before it is engineered.