What is UI?
UI, an acronym of User Interface, is a set of screens, pages, menus, tool bar, buttons, scrolls and other controls of an application. User interface determines that how easily a user can interact with the application and how much information is provided to use the application. A good user interface can provide the facility for user to use the application easily. Old computers are difficult to use because they require to operate through command line interface which is a black screen and user must type commands to operate computers. Using old computer is difficult because of its bad user interface but modern computers are easy to use because of their graphical user interface(GUI).