Surefire API

test method	Individual test method within a class
test	1..N test methods in 1 or more classes.
suite	1..N tests.
group	A named subset of test methods within a test.

How each definition is applied depends on the provider, and the test suite being used.

Directory test suite: this constructs a single suite from a directory file set. Each discovered class is treated as a test.
TestNG XML test suite: this constructs a single suite from a testng.xml file. The definitions inside the file will match those above.
JUnit 3.x: Groups are not supported.

See Surefire Providers for more information on specific providers.