UI refers to all the elements that we see inside the screen and how they relate to each other, these would be the texts, fields, images and others. After placing all the elements, the design is applied.
The priority of UX is all about the user and the experience he is going to developed, it’s the relationship before, during and after having interacted with the interface. The participation of the user is a must to understand the user and his need.
It is based on defining the ways of handling the elements, that is, the way in which information is entered or the selection of options. This includes the flow of operations and the responses that the system will generate. In conclusion is the contact between the user and the interface.