The term Usability is not something new and its importance is well known to webmasters. Despite this the concern regarding usability never gets off their minds for it is directly related to the user experience. It is one of the essential factors which are given high attention while designing and developing a website.
Usability refers to the ability of a site to allow a smooth and friendly experience to its users where they are able to find the required information in a simplified manner. In other words, the ease with which a user can utilize a site depending upon the purpose (finding information, filling a request form, making a purchase, posting feedback, etc) amounts to usability.