A Limiter and Compressor belong to the same family of dynamics processors. You can say the Limiter and Compressor are close cousins.
If you don't know what a compressor is, or need a review of it's basics,
click here.

A Limiter is just like a compressor that it prevents the signal from exceeding a threshold value. While you can use low to mid compression ratio with ordinary compressors, limiters work with very high compression ratio... like 20:1 or infinity:1. Think of it like a glass ceiling. You ain't going above the glass ceiling no matter how hard you jump up. That's what a Limiter does. It prevents the signal from going beyond that point. Just like a compressor, it also has an ATTACK time on how fast it should clamp down or limit that signal.
Very expensive limiters offer 100% guarantees that the signal will not exceed the set threshold you've set... These high-end type limiters are usualy used in the broadcast industry, PA systems and most importantly, in-ear monitoring systems. (You don't want that million dollar singer of yours suddenly go deaf because of feedback because some intern manning the FOH fell asleep.)
A good example of a limiter is the 1176LN by UREI/Universal Audio. You can also buy plugin versions of the 1176 via the
UAD-1 package. Click here to search our gear database for
limiters/compressors.
Related ArticlesHow to connect a compressorThe best compressors you can buy Build your own 1176 Compressor/LimiterBuild your own SSL Buss Compressor