What is ABS brakes ?

What is ABS brakes ? someone told me that you only need them if you drive in rains or snow, is it true ?

its anti lock braking system. it comes in handy sometimes in rain or snow. but for me it is a waste as it has almost got me in many accidents. it basically doesn't let ur wheels lock up. so that gives the driver a chance to turn the steering wheel to a safe direction. sometimes when u want to stop, it doesn't let u right away as it prevents ur wheels from locking up. and then there are cars around u so the only thing u can do is just hold down on the brake and pray to god that it stops before hitting anything.

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98 nissan 240sx turbo {summer car} 293WHP, 315WTQ at 12psi.......... goals are to reach 500whp !!
97 honda civic {winter car}
99 Mercedes ml320 {summer/winter car}

gagan has explained it quite correctly, ABS doesn't let the wheel break traction, breaking traction means complete loss of grip, what the ABS does is actually when you apply the braking force..as far as the calipers are concerned; the breaking force is applied in pulses to surface of the brake disc(you will feel the car shudder) so that it does not allow the wheels to lock up, ABS does this by simultaneously measuring the speed of each wheel, and when it gets signals from the sensors that the peripheral speed of one or more wheels is differing with the others(indicating that the tyre is about to break traction), the ABS comes into play, its advantegous to those drivers who do not know how to brake properly, in theory its supposed to reduce breaking distance..but i still maintain that a good driver can sense when his car is about to skid, and take evasive measures accordingly

An anti-lock braking system is a system on motor vehicles which prevents the wheels from locking while braking. The purpose of this is to allow the driver to maintain steering control under heavy braking and, in some situations, to shorten braking distances (by allowing the driver to hit the brake fully without skidding or loss of control). Disadvantages of the system include increased braking distances under certain conditions and the creation of a "false sense of security" among drivers who do not understand the operation and limitations of ABS.