JMeter is an open-source tool designed for performance testing and load testing of web applications. Developed by Apache, it simulates multiple users to assess application behavior under varying loads. Ideal for testing the performance of static and dynamic resources, JMeter supports various protocols like HTTP, HTTPS, FTP, and more, making it a versatile choice for developers and testers. Those interested in mastering JMeter can explore comprehensive JMeter Training in Chennai offered by FITA Academy for in-depth understanding and practical skills.