Preventive Approach: It is also known as the Verification process. Preventive is the approach to prevent defects. In this approach, tests are designed in its early stages of Software Development Lifecycle before the software has developed. In this approach, testers try to prevent defects in the early stages; it comes under Quality Analysis.
Reactive Approach: It is also known as Validation Process. This approach is to identify defects. In this approach, tests are designed to execute after the software’s development. In this approach, we try to find out the defects. It comes under Quality Control.