UI design is shorthand for User Interface design. User interface design is the creation and composition of the elements (typography, layout, buttons, etc.) that enable the user to interact with a product or service. How is UI design different from UX design? Well, if you read my last blog, you know all about UX design, but I'll summarize here.
User experience design is about creating the ideal encounter with using a product or service. The term is mainly used in relation to digital experiences, including websites, software, and mobile apps, but can also apply to the remote control to your TV, the control pad on your microwave, and the process you go through to return an item to a store. UX design is focused on figuring out what the users need.
User interface designers take all of the information, research, and wireframes from the UX designers and make it look good! A large part of enjoyable user experience is how the product, whether it be a website, a mobile app, or your cell phone, looks. A pleasing aesthetic design makes a product desirable and can lend to its credibility (2 of the 7 factors important in good UX design). The color scheme, typography, icons, imagery, visual flow are all important contributors to user interface design.
To explain further, read this quote by Don Norman, the father of user-centered design, and Jakob Nielsen, the usability consultant:
"It’s important to distinguish the total user experience from the user interface (UI), even though the UI is obviously an extremely important part of the design. As an example, consider a website with movie reviews. Even if the UI for finding a film is perfect, the UX will be poor for a user who wants information about a small independent release if the underlying database only contains movies from the major studios."
Or maybe you're a more visual learner? Try this cartoon by Patrick Hansen: