Usability Testing vs. User Testing?

Question

What is the difference between usability testing and user testing? I see them used interchangeably. Are they the same thing?

Thanks!

Answer 1

There are many ways to categorize software tests.
One of them is WHAT you test. Those are usability test, load and performance test, functional test. Another one is WHO is doing the test. Do you get other ppl who are developing other projects in your company? Do you let your customer's employees (or the targeted users, if you are developing fo a wide market) do the test? Do you just find some experts on the matter to do it? Do you hire some laymen for $5 per hour?
Both ways to categorize are basically independent, only there are combinations which don't make sense. That's why it is usual that for functionality, you do it with experts and key users, or if you do it with laymen, you get an expert to describe the expected input and expected output down to every field. On the other side, the usability test must be done with the potential users, because nobody else can say if the users will like the GUI or get confused.

Answer 2

User testing is functionality testing , Usability testing is concerned about how easy is it to use the system