Question

What is the primary purpose of 'unit testing' in software development?

Q: Answer-What is the primary purpose of 'unit testing' in software development?

Unit testing focuses on verifying the smallest testable pieces of an application typically individual functions or methods in isolation from the rest of the system, often using mock or stub objects to simulate dependencies. This is distinct from integration testing which checks that multiple components work correctly together and system testing which validates the complete, integrated system as a whole, and it typically happens earliest in the testing process, closest to when the code is written.