<p data-start="225" data-end="530">Regression testing is not a single technique but a collection of approaches used to ensure that existing functionality remains stable after changes. Different types of regression testing serve different purposes, and understanding when to apply each one helps teams balance confidence with execution time.

<p data-start="532" data-end="759">Unit regression testing focuses on verifying individual components after small code changes. It is fast, highly targeted, and useful during early development stages, but it does not validate interactions between components.

<p data-start="761" data-end="994">Partial regression testing is applied when changes affect specific areas of the system. Only tests related to the modified modules and their dependencies are executed, making it an efficient option when impact is well understood.

<p data-start="996" data-end="1226">Complete regression testing involves running the entire test suite. This approach is typically used after major releases, large refactors, or infrastructure changes where the potential impact is broad and difficult to predict.

<p data-start="1228" data-end="1504">Selective regression testing prioritizes tests based on risk, change history, and business criticality. Instead of executing all tests, teams run high-value scenarios that protect core workflows and shared services, improving feedback speed without sacrificing confidence.

<p data-start="1506" data-end="1714">Progressive regression testing ensures that new features do not disrupt existing behavior as the product evolves. Tests are added incrementally, expanding the regression suite alongside new functionality.



<p data-start="1716" data-end="1970">Choosing the righttypes of regression testing depends on the scope of change, system complexity, and release cadence. Applying the appropriate approach at the right time helps teams maintain stability while continuing to deliver improvements efficiently.