Performance

Performance is a quality attribute that measures how well a system responds to client or user interactions.

Perceived performance is a subset of performance that focuses on the responsiveness of a system in acknowledging user actions, rather than the longer time it takes to process those actions. Perceived performance is often harder to measure, because it depends (in part) on the users' perceptions of the system’s responsiveness.

Optimization techniques vary widely depending on the requirements and constraints of the system, and are largely dictated by access patterns. For example, a system with read-heavy workloads will be optimized very differently to one with write-heavy workloads.

Performance is synonymous with speed and responsiveness. It is closely related to latency, which refers to measurements of the time it takes for a system to respond to input.

Colloquially, the term "performance" is widely used as a catch-all term for how well a system meets all of its functional and non-functional requirements. Thus, a high performing system may be regarded as one that strikes a good balance between [latency], [throughput], [scalability], [availability], [reliability], [efficiency] of resource utilization, and other quality attributes.