User Experience is all about making the product, service, or interface work as perfectly as possible. UX research companies cater to their users and find what they like and do not like. By researching their customers, they can fix the problems and better the UX. On the other hand, User Interface is all about making the interface the most pleasing. People want a nice and organized interface that they will not get lost in. UI companies have different methods to make the UI how the user would like and work mainly on this goal. UX and UI can be viewed as related but they are definitely not the same.
User Experience wants to improve the overall product or service, as User Interface wants to connect the people with the interface. By focusing on UX, the customers most important needs are met. With UI, the customer’s experience is better by making the interface how they would like it. UX is what makes the product or service actually work and UI is all about making the interface of the product or service look nice.
When working with UI it only applies to interfaces because that is what it is trying to improve. UX applies to products, services, and even interfaces because if the user is interacting with it then the UX can always be improved. User Experience is a lot broader of a term used because it applies to more than one thing. UX tends to be a lot more complicated while UI focuses on small changes to the interface.
In the process of creating a product or service, UX comes first most of the times. Without UX, there would be no UI because the company would not have a user compatible product or service. Since UX is more complex, it must be fixed first before the UI can be improved. If you were to work on the UI first and the then adjust the UX, you might run into some problems and have to redo the interface.