In software testing, what does a driver do?

In software testing, a driver serves as a simulation for a called component that is not yet developed or is incomplete in some way. It allows the testing of individual units or components in isolation by providing the necessary interface for invoking functions or methods of the component under test.

When a driver replaces an incomplete component, it helps to facilitate a testing environment where the functionality of the unit can be validated even if other dependent modules are not available. This ensures that developers can continue to work on different parts of the software without waiting for all components to be fully developed. By using a driver, testers can focus on verifying the behavior and performance of the component under test while maintaining a continuum in the development process.

Other options do not accurately characterize the role of a driver in the testing process, thereby reinforcing the focus on the right function and utility of a driver in unit testing scenarios.