The term UX was coin by Jesses James Garrett, who defined the UX model, the 5 planes of user experience. The idea is that no matter what you are building you must follow the 5 planes of user experience.
We starts of with Strategy, which is a very abstract idea and work through the 5 Planes of UX until we come to Surface which is where the abstract idea becomes real and a finished product.
Strategy – User needs and Business goals, what do users need, what does business need to gain ?
Scope – requirements and specifications, what are we building and what functionality do we need.
Structure – Information architecture, how is it organised.
Skeleton – How do users navigate, how is the workflow, the layout of the screen. Wireframing where everything goes.
Surface – Styling, Fonts, Images, how it looks. (Concrete Design). Where the abstract idea becomes real and a finished product.