Sanity Testing
Sanity testing is a narrow, focused check that a specific bug fix or small change works as intended and hasn't obviously broken the immediate area around it. It's quicker and shallower than a full regression test, meant purely to confirm "this makes sense" before deeper testing continues.
Sanity testing and smoke testing are often mixed up, but they differ in scope: smoke testing checks the overall health of a whole build (does it even start, does login work); sanity testing checks one specific, narrow area right after a change, without going deep into surrounding functionality.
A typical sequence: smoke test the build first to confirm it's stable enough to test at all, then sanity test the specific fix or feature that just changed, before committing to a full regression pass across the whole application.
