In general, the term refers to the extent of convenience in using a particular object while completing a task. Usability in UX is a quality mark of simplicity and comfort in using a digital product (or a part of it).
Usability is measured in five dimensions:
- Ease in navigation and intuitive design: the user successfully orients in the product
- The simplicity of learning: the user adapts to the interface fast
- Efficiency: effortlessly completes tasks in a short while
- Memorability: a single interaction with the interface lets using it without
complications in future
- Error frequency: how often the user faces system mistakes and does it himself