The user interface is the first level of user interaction with the product, so it is essential how the product is seen at first sight.
User Interface Design (UI) is a space that occurs between user and machine. The user interface is the visible and tangible part of a product that the user directly deals with.
A user interface consists of menus, windows, icons, etc. One of the essential parts of an application is the user interface. The user interface determines the difficulty or ease of an application to use.