Definitions of Rich User Experience (IV)

User Experience (UX or UE) encompasses all aspects of a digital product that users experience directly—and perceive, learn, and use—including its form, behavior, and content. Learnability, usability, usefulness, and aesthetic appeal are key factors in users’ experience of a product.
Pabini Gabriel-Petit
 User Experience (UX or UE) encompasses the visual appearance, interactive behavior, and assistive capabilities of software. From an application's graphical user interface to its use of additional technologies such as speech recognition and speech synthesis, a cohesive and professional user experience is what Mac users have come to expect.
Apple Leopard Reference Library