What does the CA and CCA rating on a battery mean?

Cranking amps are the numbers of amperes a lead-acid battery at 32 degrees F (0 degrees C) can deliver for 30 seconds and maintain at least 1.2 volts per cell (7.2 volts for a 12 volt battery).

Cold Cranking amps are the number of amperes a lead-acid battery at 0 degrees F (-17.8 degrees C) can deliver for 30 seconds and maintain at least 1.2 volts per cell (7.2 volts for a 12-volt battery).

It is more difficult for a battery to deliver power when it is cold out so the CCA rating is the best one to go by. It isn't fair to compare the two ratings, the CA is generally used by places that want their batteries to sound stronger than they are.