The Apache JMeter desktop application is open source software, pure Java application designed to load test functional behaviour and measure performance.
Features of JMeter :-
1. JMeter helpful in making and Executing Test plans like simulate logging into a web site, simulate middle-ware and Database jobs , Generate and Automate real time application (Desktop/Mobile) scenarios etc.
2. Also helpful in simulating the number of users doing this, the rate at witch they do it.
3. It also helps for regression test by creating Assertions (Checkpoints) using regular expressions.