Apache JMeter is a open source software, a 100% pure Java desktop application designed to load test functional behaviour and measure performance of a software/web-based packages. It was originally designed for testing Web Applications but has since expanded to other test functionality as well.
In simple words
‘Apache JMeter is Java application designed to load testing the application. You can use JMeter to test how much load your Website can handle.’
How it will be helpful?
Apache JMeter is used to test functional and performance both on static and dynamic resources (files, Servlets, Perl scripts, Java Objects, Data Bases and Queries, FTP Servers, PHP Scripts and more).
JMeter is not a browser as it looks like. As far as web-services and remote services are concerned, JMeter looks like a browser (or rather, multiple browsers); however JMeter does not perform all the actions supported by browsers.
How can I get JMeter ?
Click on the link below.
A complete manual of the same can be found here.
Hope this will help..