In a new post on her blog Jessica Mauerhan has some good examples on the various types of test doubles.

Did you know that a Mock is only one type of a test double? Most of us use the word “mock” to mean any kind of test double, but there’s actually five different types. It really can help you understand what you’re trying to accomplish with your test if you know a little bit more what you’re doing with your test doubles, so this article will explain the kinds of test doubles, when you use them, how you use them and why.