Plugin delay compensation (PDC)
The DAW feature that delays every other track by as much as the slowest plugin, so the kick and the bass still land together.
Plenty of effects can't deliver their output the instant audio comes in. A lookahead limiter needs to see a few milliseconds ahead, a linear-phase EQ relies on long filters and a convolution reverb works in blocks. The plugin therefore reports its delay in samples to the host, and the host holds back the other tracks and buses by the same amount so everything lines up in the mix.
Without compensation, a parallel-compressed drum suddenly sounds phasey, because the same signal arrives twice a few milliseconds apart. With it the mix works, but total latency becomes that of the slowest track — which is why the heavy effects get switched off while recording. Outboard hardware inserts can't report anything on their own; there you measure the delay and type it in by hand.