testing

Testing is the process of evaluating a system or its components to determine whether it meets specified requirements and quality standards. It aims to identify defects, assess performance, and provide information for decision making. Testing is applied in many fields, including software development, hardware manufacturing, education, and science.

In software engineering, testing is a verification and validation activity that confirms a product behaves as intended under defined conditions. It distinguishes functional testing (what the product does) from nonfunctional testing (how well it does it), and from white-box and black-box testing approaches. Common levels include unit testing, which checks individual components; integration testing, which verifies interactions between components; system testing, which validates the complete system; and acceptance testing, which judges readiness for release by stakeholders. Other forms include regression testing, performance or load testing, security testing, and usability testing. Testing is supported by test design techniques, test data, and test environments, and is guided by plans and test cases. Defects are logged and tracked with a formal process, and metrics such as defect density, test coverage, and pass rate are used to assess progress.

In manufacturing and quality assurance, testing validates that products meet specifications before shipment. In science, experiments test hypotheses under controlled conditions, using statistical analysis to draw conclusions.

Standards and best practices, such as established testing standards and test documentation, help ensure repeatability and quality across organizations while enabling risk-based prioritization.