Testing: Definition and Types

Testing is the process of evaluating a system or its components with the intent to find whether it satisfies the specified requirements. Types include unit, integration, system, and acceptance testing.

Unit testing focuses on individual components or pieces of code. It ensures that each part functions correctly in isolation. This testing level is foundational for verifying the reliability of code blocks.

Integration testing evaluates the interaction between modules. It's crucial for uncovering issues where units, tested separately, fail to operate together. This uncovers interface defects among integrated components.

System testing examines the complete, integrated system to assess its compliance with its specified requirements. It goes beyond components to check the end-to-end system functionality and performance.

Acceptance testing, often the final phase, determines if the system is ready for release. Real-world scenarios and criteria set by clients or end-users are applied to validate the product's readiness.

Automated testing isn't just for large enterprises. Surprisingly, it's accessible to startups too, thanks to open-source tools. Automated tests can run 24/7, increasing productivity and reducing time-to-market.

The first known testing practice dates back to the 1950s. However, it was only in the 1980s that testing was recognized as a distinct discipline, with the founding of the International Software Testing Qualifications Board (ISTQB) in 2002 marking a professional milestone.