User experience, often abbreviated UX, is a term used to describe the overall experience and satisfaction a user has when using a product or system. It most commonly refers to a combination of software and business topics, such as selling over the web, but it applies to any result of interaction design.
This field has its roots in human factors and ergonomics, a field that since the late 1940s has been focusing on the interaction between human users, machines and the contextual environments to design systems that address the user's experience. The term also has a more recent connection to user-centered design principles and also incorporates elements from similar user-centered design fields:
• Human computer interaction
• Information architecture
• Interaction design
• Interface design
• User interface design
• Usability
• Usability engineering
• Visual design
As with the fields mentioned above, user experience design is a highly multi-disciplinary field, incorporating aspects of psychology, anthropology, computer science, graphic design and industrial design.
At its core, user experience design incorporates most or all of the above disciplines to positively impact the overall user experience with a particular system or device. User experience design defines a sequence of screen presentations, user interactions, and system responses that meet user goals and tasks while satisfying business and functional requirements
(source Wikipedia)