Do you mean Lautering? Lagering? Or Laughtering?
Lautering is the step in all grain brewing when you drain off the sweet wort from the grains. Read John Palmer's free "How to Brew" book, available online, to learn more.
Lagering is when you hold a beer under cold conditions to help it clear and age. Normally this is done with bottom fermenting lager yeast. However, you can technically "lager" an ale as well. The german style known as altbier is one example of this. Again, read Palmer's free online book to learn more.
Laughtering is when you stick a cat inside a 15 gallon keggle and sprinkle in a little catnip. I don't think Palmer covers this method in his book as it's a more advanced technique intended for experienced brewers....
Hope that helps!