Apache JMeter is open source software, which is also a pure Java desktop application, designed to load test functional behavior and measure the performance of web sites. Even though it was originally designed for load testing web applications but has since expanded to other test functions since its inception.
JMeter can be used for test plan building, load test running, and load test analysis. It has a GUI mode that allows you to create test plans manually, choose from a variety of templates, or record the application from a browser session. GUI mode also allows for debugging and viewing results. Arranging scripts takes very little time and resources, and it is simpler because it does not require managing different agents.
JMeter simulates a group of users sending requests to a target server, and returns statistics that show the performance/functionality of the target server/application via tables, graphs, etc. It is user-friendly and has a comprehensive GUI, which helps to create a test plan and configure the elements.