Categories of performance testing

Performance testing : Performance is concerned with achieving response times, throughput, and resource-utilization levels that meet the performance objectives for the project or product

Load testing : Validating performance characteristics of the system or application under test when subjected to workloads and load volumes anticipated during production operations

Stress testing : Validating performance characteristics of the system or application under test when subjected to conditions beyond those anticipated during production operations. Stress tests may also include tests focused on determining or validating performance characteristics of the system or application under test when subjected to other stressful conditions, such as limited memory, insufficient disk space, or server failure. 

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