Is it farther or further?
(Or "application testing") A type of testing to confirm that all code modules work as specified, and that the system as a whole performs adequately on the platform on which it will be deployed.
System testing should be performed by testers who are trained to plan, execute, and report on application and system code. They should be aware of scenarios that might not occur to the end user, like testing for null, negative, and format inconsistent values. A tester should be able to repeat the steps that caused an error.