What is the purpose of regression testing in software development?

Regression testing plays a crucial role in ensuring the reliability and stability of software when changes are made, whether those changes are bug fixes, enhancements, or other modifications. The primary purpose of regression testing is to verify that the introduction of new code or alterations does not adversely affect the existing functionality of the software. By running regression tests, developers can confirm that previously functioning features remain operational and that no unexpected behaviors have emerged as a result of recent changes.

The process involves re-executing a subset of tests that validates both the new features and the older parts of the application to ensure comprehensive coverage. This helps in safeguarding against potential defects that could arise from interactions between new and existing code, thereby maintaining software quality over time.

Other choices do not align with the core purpose of regression testing. Introducing new features is more closely associated with functional testing, while code reviews focus on examining the quality of code for issues rather than verifying functionality. Enhancing code efficiency pertains to optimization efforts and does not specifically address the verification of existing system functions.