Usability is the ease, speed, and pleasantness with which intended users can use a software application. Usability is a concern in the design of any product used by humans. It is perhaps more important to the software industry because of the intangible nature of software. If a software application is poor in usability, users are less productive, commit more errors, and are dissatisfied with the software. Software companies and end-user organizations miss the business benefits that result from highly usable applications.
Users are happier doing things with a usable software.
Software companies and end-user organizations derive benefits too. More specifically, the basic interaction style and menu structure are appropriate for them and the work they perform. The software provides adequate feedback when users need or expect them. Fields and other objects are meaningfully grouped and ordered. The names given to menus, fields, windows, and other screen objects make immediate sense to the users.