A Drop Down is GUI functionality in which we can create Drop Down menu and Lists in horizontal list with vertical menus. When we click on the Drop Down menu and list we can see multiple further options. In easy means we can say Drop Down is basically used for to reduce the complexity of codes for more GUI options. Drop Down menus are also commonly used for website navigation. Many websites use Drop Down menus to provide users with direct links to more pages than standard navigation bars allow. In web development Drop Down menu play an important role for Designing a good GUI environment and reduce the work complexity.