Performance Testing is a software testing process used to evaluate a software application's speed, response time, stability, reliability, scalability, and resource usage under the expected workload. 

Performance tests are typically executed to examine speed, robustness, reliability, and application size. Performance testing goals include evaluating application output, processing speed, data transfer velocity, network bandwidth usage, maximum concurrent users, memory utilization, workload efficiency, and command response times. 

Shortly, the goal of Performance Testing is not to find bugs but to eliminate performance bottlenecks.