what's the difference between these 2 intakes besides that one sucks in cold air and other one sucks in what ever air is around. whats the difference in the design

 

a Cold Air Intake (CAI) is usually built longer than your standard intake. It usually drops all the way down your engine bay to suck in all the cold flowing air, rather then the air inside your engine which would be warmer. Warmer air = less HP. The cooler your engine runs the better it performs.
However the drawback is this - CAI's can be hazardous to your car if you manage to run into a puddle. These intake may suck in water which could be..............well BAD. However there are usually bypass valves which protect the intake a little better.