User Experience is an all-encompassing term that describes facets of development that affect the experience of the end user in the use of the system; UX/UI addresses the design and development of the human-computer interaction patterns through which the system is experienced and data is consumed and transacted.
User Experience is often thought of as interchangeable with User Interface, but in truth UX includes many other factors beyond the design and engineering of the user interface. UX might be affected by the ease of finding the user interface for a system -- or a specific system function -- in the website, or it might be affected by how well we have brought interactions with data from multiple systems into a given workflow. UX involves graphic design, layout, usability, etc. as well as primary research through focus groups and usability tests to determine levels of satisfaction and areas for improvement.
Some best practices related to user experience are as follow: