Can someone explain cold crashing

can someone explain cold crashing to me? what is the process, which type of beers do you do that too and what exactly is the benefit to the beer?

thanks.

You get the beer as cold as possible. It quickens the process for the beer to clear. IE yeast and other solids dropping out of suspension, flocculation

In case you are wondering why not cold crash, the answer typically is that you want the yeast to keep on workin through the time that you step the temperature down. For example, some lagers and hybrids benefit by yeast continuing to do things as the temperature is dropped slowly (sometimes it is going a few points lower for FG, other times it is just yeast cleaning up, and there may be mysterious things that happen which are not yet known.). Essentially, if your beer is at the gravity that you want it at, you can cold crash then rack. Lagers may justify more time at the crash temp than ales, traditionally.