Contract API vs Regression

The table below describes various differences between Contract and Regression Test Types.

Aspect	Contract API Testing	Regression Testing
Focus	Contracts and agreements between services or APIs	Overall application functionality and features
Purpose	Ensure adherence to communication contracts	Identify and prevent regression (new defects)
Scope	Limited to interactions between specific services	Broader, covering the entire application or modules
Timing	Often during the development of individual services	Typically after code changes, part of release cycle
Coverage	Specific contracts, request/response formats	Comprehensive, various test cases for diverse features
Application Stage	During service/component development	After code changes, part of the software release cycle
Primary Concern	Communication protocols, data structures	Stability and integrity of existing functionality