Which type of testing is typically performed before integration testing?

The correct answer is unit testing, which focuses on verifying the functionality of individual components or modules of a software application. This type of testing is performed early in the development process, allowing testers and developers to identify and fix bugs at a granular level before those components are combined into larger systems. By ensuring that each unit functions correctly, unit testing lays a solid foundation for the subsequent integration testing phase, where multiple components are tested together to verify their interactions.

Unit testing is crucial because it tests the smallest parts of the application in isolation, making it easier to pinpoint issues directly related to specific code elements. This proactive approach to identifying defects can lead to reduced debugging time and improved overall software quality as the project moves forward into integration and system testing stages. Integrating properly tested units supports a smoother transition to further testing levels, ensuring that integration testing can focus on interactions and integrations between components rather than on basic functionality errors.

In contrast, system testing evaluates the complete and integrated software product, acceptance testing verifies whether the system meets business requirements and is ready for delivery to users, and performance testing assesses how well the system performs under various conditions. These types of testing occur after unit testing has been successfully completed and are not intended to verify individual components, which is the primary goal of