Regression testing is an important part of the software life cycle (birth and death). It's cumbersome, but it is a test done to verify the previous round of modifications during regression testing. The purpose is to verify that bugs have been fixed and that the repair process has introduced new bugs. Multiple regressions are performed at various stages of testing. Usually after having already gone through the first round of system testing or even several rounds of system testing.
The focus of the test: bug modification, related functions, newly added functions, modified functions, and functions with many bugs in the previous round of testing. (Testers need to know which bugs have been modified in this round, and pay attention to the changes in our bug management tool.)
How to do regression well: 1. Change testers, regression is cumbersome, you can reduce the boredom of one person doing regression through the rotation of testers,
2. Use automation.