What visual regression testing is, how image comparison works, and the vocabulary teams use to talk about it.
The visual defects that reach production most often — overflow, z-index stacking, font fallback shift, broken empty states — what causes each one, and the cheapest way to detect it automatically.
Plain definitions for the vocabulary of visual regression testing — baseline, checkpoint, snapshot, threshold, masking, TurboSnap, perceptual diff, flake, and the rest.
The terms get used interchangeably and they are not the same thing. Screenshot testing is the capture mechanism; visual regression testing is the practice built around comparing, reviewing, and approving those captures.
Visual regression testing compares screenshots of your interface before and after a change to catch layout and styling bugs that functional tests pass straight through.