newbie questions

[Leandro Saad]

Hi all, I'm new to this list and I apologize if this has been already
answered before.
I installed the sample on my machine and I'm trying to figure out how it
works : there is a ant task that get's executed and calls
TestSampleServlet. TestSampleServlet.suite() says that every method
beginnig with "test" should be executed.
My question is , finally, what/how are those classes in unit/ used for
????