What does the term 'usability' define in the context of UX?

The term 'usability' in the context of User Experience (UX) specifically relates to the ease with which users can achieve their goals when using a product. This encompasses how intuitive and accessible the product is, allowing users to navigate it without confusion or frustration. High usability means that users can effectively and efficiently complete their tasks, which significantly enhances their overall experience with the product.

Usability involves several key elements, including learnability (how easy it is for users to accomplish basic tasks the first time they encounter the design), efficiency (once users have learned the design, how quickly can they perform tasks), memorability (how easy it is to reestablish proficiency after a period of not using the design), and error management (how many errors users make, how severe the errors are, and how easily they can recover from them).

In contrast, the other options touch on different aspects of user experience. The emotional response (option A) relates to feelings and sentiments rather than the practical functionality. Aesthetic quality (option C) focuses on visual elements and design appeal, while market demand (option D) pertains to economic factors and user interest rather than usability itself. Thus, option B effectively captures the core essence of usability in UX.