Which testing phase is performed to ensure components work together?

Integration testing is the phase of testing that is specifically designed to verify that individual components or modules of a system interact and function together correctly. This type of testing focuses on the interfaces and the interaction between integrated components, ensuring that they communicate as expected and that data is passed between them without issues.

During integration testing, testers will typically examine how multiple units work together, looking for defects that arise only when components are combined. This is crucial because individual units may perform well in isolation during unit testing, but when brought together, their interactions can lead to unexpected behavior or failures.

In contrast, unit testing focuses on testing individual components or functions in isolation, without considering their interaction with other components. System testing evaluates the complete and integrated software system to ensure it meets the specified requirements, while acceptance testing assesses the system's readiness for use from the user’s perspective. Thus, integration testing is essential for confirming that all parts of the software work together harmoniously before moving on to broader testing phases.