Which type of testing focuses on the functionality of a specific component?

Unit testing is a testing methodology that focuses specifically on the functionality of individual components or modules within a software application. The goal of unit testing is to validate that each unit of the software performs as intended. Typically, unit tests are written and executed by developers during the development process to catch issues early and ensure that code behaves as expected when given specific inputs.

Unit testing often involves examining small parts of code, such as functions or methods, in isolation from the rest of the program. This granular approach helps identify bugs at the earliest stage, allowing developers to address issues before they propagate to higher levels of integration or system testing. By concentrating on specific components, unit testing lays a robust foundation for overall software quality.

Other testing types, such as integration testing, focus on interactions between components or systems, system testing assesses the complete system's compliance with specified requirements, and acceptance testing evaluates the system's readiness for deployment from the user's perspective. Each of these serves a different purpose in the software development lifecycle, highlighting why unit testing is uniquely positioned to focus on individual component functionality.