Warp markers
Pins that fix a point in an audio file to a specific bar and beat on the DAW's grid, so the audio between them is stretched to fit.
A live drum recording drifts in tempo. Put a marker on every beat, drag each one to its grid line, and the software works out how much every slice between markers has to be stretched or squeezed; time-stretching does the rest. The same mechanism lets a loop recorded at 92 BPM play at 128 without changing key.
Ableton Live built its whole workflow around this from version 1.0 in 2001, and the word warp came with it. Logic calls it Flex Time, Pro Tools calls it Elastic Audio. The software places markers automatically at transients, and mostly gets them right; the rest of the time it explains why the drum loop sounds like it has hiccups.