User experience (UX) is about how a person feels about using a
product, system or service. User experience highlights the
experiential, affective, meaningful and valuable aspects of
human-computer interaction and product ownership, but it also includes
a person’s perceptions of the practical aspects such as utility, ease
of use and efficiency of the system. User experience is subjective in
nature, because it is about an individual’s feelings and thoughts
about the system. User experience is dynamic, because it changes over
time as the circumstances change.
To me, User Experience (UX) is the complete and holistic experience someone has with a system. Some examples:
- The UX of communism includes the way you feel about your job.
- The UX of my cell phone service includes the feel of the phone in my hand.
- The UX of DirecTV includes the automated voice system when you call for support.
- The UX of my car includes the price.
- The UX of StackExchange includes the FAQ as well as the UI.
All of these things affect how I feel about the product/service/system. The goal of UX is to influence outcomes like referrals, sales, safety, etc. UX is (to a large degree) applied psychology. It is designing things to elicit a desired response.
This question is pretty broad, but I hope this helps.