Usability Testing is defined as a type of software testing where, a small set of target end-users, of a software system, “use” it to expose usability defects. This testing mainly focuses on the user’s ease to use the application, flexibility in handling controls and the ability of the system to meet its objectives. It is also called User Experience(UX) Testing.
Users are asked to complete tasks, typically while they are being observed by a researcher, to see where they encounter problems and experience confusion. If more people encounter similar problems, recommendations will be made to overcome these usability issues.
The key difference between usability testing and traditional testing (bug testing, acceptance testing etc.) is that usability testing takes place with actual users or customers of the product. Whilst traditional testing might be undertaken by a developer, designer or project manager, usability testing removes any bias by collecting feedback direct from the end user.