Limiters
Limiters are that sound level gate or guard that prevents the dynamic level from exceeding a set decibel number. So any sound that tends to be louder than the set limit, it wont go over an will remain within the same range of everything else in a song.
You have to however, take care to not use limiters excessively. When you apply too much limiter, you begin to rob the song of it's dynamics. In this over processed state the song can sound weird with no distinction between soft or loud sounds because everything in the audio will basically sound low. There is no perception of energy in the song in this way.
So limiters are helpful when you want to just trim off those sharp spikes in volume during playback that can sometimes cause clicks & pops because the level has exceeded 0db. This is unacceptable an will make the final master not ready for reproduction. Limiters do their job by keeping all those high level spikes in check.
