User experience (UX or UE) is about how a user interacts with, and experiences, a particular product, system or service. It includes a person's perceptions of utility, ease of use, and efficiency. User experience is an important concern to many companies when creating products, as negative user experience may decay profitability. User experience is subjective.
UX design is the process of supporting user behaviour through usability, usefulness and desirability provided in the interaction with a product. UX extends itself by addressing all aspects of a product or service as perceived by users.