about FACS - the fluorescence (Dec/15/2006 )

There are several kinds of fluorescence, PE, APC, FITC and so on.
Is there somebody could tell me the differences among them?
Thanks~

I found this good link about fluorescent dyes for flow Cytometric analysis.

http://www.ebioscience.com/ebioscience/appls/Dyes.htm

Thanks a lot~