While UX (user experience) and UI (user interface) go hand-in-hand for a successful product, the roles of the two design disciplines are very different. Don Norman, the cognitive scientist that coined the term UX in the early 1990’s, wrote a more recent article in which he highlights the blurred lines and interdependence between these fields:
“True user experience goes far beyond giving customers what they say they want, or providing checklist features. In order to achieve high-quality user experience in a company's offerings there must be a seamless merging of the services of multiple disciplines, including engineering, marketing, graphical and industrial design, and interface design.”
That being said, there are distinct responsibilities and expertise involved that distinguish one profession from the other. UX designers focus on how the product feels. They approach a project in an analytical manner, the main concern being that the product logically flows through each point in an interaction. To achieve this outcome, UX designers utilize user research, personas, usability testing, wireframes, and information architecture.
UI designers are responsible for creating a graphic layout that visually communicates the path created by a UX designer. Color, typography, interactive element placement, and brand language are all critical components to UI designers, but there is also involvement with developers and code.
The roles of the UX and UI designer can vary from place to place, even overlapping in some instances to create a “hybrid” UX/UI role. The responsibilities of these disciplines are also found under different titles; for example, the term “web designer” is often used define UI designers that can code. Rule of thumb, don’t decide on a designer by their title, but rather by the compatibility of their skills and a projects needs.