What type of data does performance testing focus on?

Performance testing is primarily concerned with evaluating how a system behaves under specific conditions, especially when subjected to various levels of load. This involves assessing system parameters such as response time, throughput, resource usage (like CPU, memory, and disk I/O), and scalability. The objective is to ensure that the application can handle a certain amount of traffic and perform optimally within acceptable thresholds.

By focusing on system parameters and behavior under load, performance testing helps identify bottlenecks, determine maximum capacity, and ensure a reliable and efficient user experience. The emphasis is on quantifiable metrics related to system performance rather than subjective elements or external factors such as marketing data or user interaction logs. Understanding how a system responds under stress is crucial in developing robust applications that maintain functionality and performance in real-world scenarios.