User interface design (UI) or user interface engineering is the design of user interfaces for machines and software, such as computers, home appliances, mobile devices, and other electronic devices, with the focus on maximizing usability and the user experience. The goal of user interface design is to make the user's interaction as simple and efficient as possible, in terms of accomplishing user goals (user-centered design).Good user interface design facilitates finishing the task at hand without drawing unnecessary attention to itself. Graphic design and typography are utilized to support its usability, influencing how the user performs certain interactions and improving the aesthetic appeal of the design; design aesthetics may enhance or detract from the ability of users to use the functions of the interface.

User experience (UX) design is the process of creating products that provide meaningful and personally relevant experiences. This involves the careful design of both a product’s usability and the pleasure consumers will derive from using it. It is also concerned with the entire process of acquiring and integrating the product, including aspects of branding, design, usability, and function. An important concept in UX design is the process by which users form experiences. When first encountering a product, a user forms a momentary impression—which evolves over time, typically as the product is used throughout a period. In this process, the user’s perception, action, motivation, and cognition integrate to form a memorable and coherent story: called “the user experience.” This process elicits emotional responses, which largely determine whether the experience will be considered positive or negative.