Explain path testing. 

Ans:
Path Testing: Testing in which all paths in the program source code are tested at least
once. Path testing has been one of the first test methods, and even though it is a typical
white box test, it is nowadays also used in black box tests. First, a certain path through
the program is chosen. Possible inputs and the correct result are written down. Then the
program is executed by hand, and its result is compared to the predefined. Possible
faults have to be written down at once.