User Experience (UX) is all about understanding for whom you are designing. By understanding the (goals of the client or project and motives of your audience, you can create a product that is specifically tailored to their needs and the needs of the client). With ever-growing global competition, it is incredibly valuable to understand who is using you product or service inside and out. By doing research and conducting tests, User Experience concentrators make sure their products do what they are supposed to do.
Design and Redesign
To make sure that the interface works how it should, UX designers test and retest things until they are as good as they can be. They make revisions based on the test results to make a product that suites their user's needs.