What type of testing is performed to ensure that separately developed software modules properly exchange data?

The focus of the question is on verifying that independently created software modules are able to properly communicate and share data. This specific requirement is best met through interface testing, which is designed to evaluate the interactions between different software components or systems.

Interface testing ensures that the interfaces between modules communicate correctly, achieving the expected functionality, and handles cases such as data formats, protocols, and error handling. By testing only the boundaries between these modules, it verifies that inputs and outputs are passed correctly between them, ensuring data integrity and overall system reliability during integration.

While integration testing does assess how well modules work together as a whole, it generally encompasses more extensive interactions beyond just the interfaces—it focuses on the behavior and performance of combined modules. Therefore, interface testing is more precise for the context of examining data interchange between specifically developed software components.