User experience (UX) refers to the overall experience a person has when interacting with a product, system, or service, particularly in terms of how enjoyable and efficient that interaction is. It encompasses various aspects, including usability, accessibility, and satisfaction, which contribute to how users perceive their interaction with a user interface. A strong focus on UX is essential in cognitive ergonomics and user interface design to ensure that products not only meet user needs but also align with cognitive processes.