CRC is superior to a simple checksum in that it is much more unstable when errors occur....to screw up a checksum, all you have to do is switch a 1 to a 0, then later, switch a 0 to a 1 in the same position. Not common, but common up to be irritating when it passes. To get an identical CRC, you would have to really really hose your transmission, then cross your fingers and pray that the random values you pass have the same CRC value as what you started with.

CRC also stands for the Chemical Rubber Company, who put out the CRC Handbook of Chemistry and Physics.