... is a simulation of a real object.

... is created to test the behavior of a real object.

... act just as real objects but in a controlled way.

... is the virtual database relation.

... is created in order to prevent the application from errors.

With the use of mocks, we can verify that the methods we set up are being called during the execution of the tested cases.

With the use of mocks, we can set up the object, including setting parameters and return values on the function calls. 

A mock object allows us to copy or clone the behavior of a class and interface.

A mock object is the custom type to imitate the behavior of one method.

The method’s return type should be void.

The method must be declared protected.

The method’s return type is not responsible

The method must be declared public.

Setup method arranges specific logic for every test method or performs necessary preparations that are appropriate to a specific test method within a test suite or test class.

The Setup method will be called every time before the execution of every test. 

The Setup method will be called once, before the execution of all test cases within a test class. 

Setup method arranges common mocking logic for all test methods or performs necessary preparations that are shared among multiple test methods within a test suite or test class.