User-Centered Design (UCD) is the process of designing a tool, such as a website’s or application’s user interface, from the perspective of how it will be understood and used by a human user. U sability is important because it can make the difference between performing a task accurately and completely or not, and enjoying the process or being frustrated. I t can also mean the difference between the success or failure of a system. The Four User Interfaces are: Graphical, Touch, Voice, and Augmented Reality. Graphical User Interfaces relies on the sense of sight. These are things like buttons, icons, scrolling bars, desktops and menus. Touch User Interfaces is a comp uter-pointing technology based upon the sense of touch. A TUI enables not only the sense of touch to innervate and activate computer-based functions, it also allows the user, particularly those with visual impairments, an added level of interaction based upon tactile or Braille input. Voic...