Not daft m8 put simply the higher the cold crank in colder temps the better chance your car will turn over and start.
Cold Cranking Amps (CCA)
CCA is a rating used in the battery industry to define a battery's ability to start an engine in cold temperatures. Generally speaking, it is easier to start an engine in a warm environment than in a cold one. The rating refers to the number of amps a 12-volt battery can deliver at 0°F for 30 seconds while maintaining a voltage of at least 7.2 volts. The higher the CCA rating, the greater the starting power of the battery.