Soak testing involves testing a system with a significant load extended over a significant period of time, to discover how the system behaves under sustained use. Soak testing is bassically called as Endurance Testing.running a system at high levels of load for prolonged periods of time. A soak test would normally execute several times more transactions in an entire day or night than would be expected in a busy day, to identify any performance problems that appear after a large number of transactions have been executed. Its bassiclaly A quick-and-dirty test that the major functions of a piece of software work. Originated in the hardware testing practice of turning on a new piece of hardware for the first time and considering it a success if it does not catch on fire.