Limiters eliminate the parts of a signal that are above a set decibel limit or threshold.

Compressors, on the other hand reduce – not eliminate – the peaks of a signal above a set threshold. So, the difference is that while compressors reduce the amount of signal above the threshold by a percentage, limiters do not allow any peaks above the threshold.

Limiter is essentially a compressor with compression ratio of infinity to one. By creating a hard ceiling, limiters prohibit peaking.