Usability testing: it is a non-functional testing technique that is a measure of how easily the system can be used by end users. It is difficult to evaluate and measure but can be evaluated based on the below parameters:

• Levels of Skill required learn/use the software. It should maintain the balance for both novice and expert user.

• Time required to get used to in using the software.

• The measure of increase in user productivity if any.

• Assessment of a user's attitude towards using the software.

GUI testing :

• GUI testing is the process of testing the system's Graphical User Interface of the Application Under Test. GUI testing is the process of ensuring proper functionality of the graphical user interface (GUI ) for a given application and making sure it conforms to its written specifications.

• In addition to functionality, GUI testing evaluates design elements such as layout, colors, fonts, font sizes, labels, text boxes, text formatting, captions, buttons, lists, icons, links and content. GUI testing processes can be either manual or automatic, and are often performed by third -party companies, rather than developers or end users.

• GUI is what user sees. A user does not see the source code. The interface is visible to the user. Especially the focus is on the design structure, images that they are working properly or not.