We start with the electric motor. The motor pulls electricity from your ATV's battery and converts it into power. The motor turns the gears in the gear train. The smaller gears in a planetary gear train turn faster than the larger ones in a worm gear train. In either case, the gear train creates torque and turns the drum.
What's torque? Torque is the measure of a force's ability to rotate about an axis. It turns or tends to turn an object. In the case of winches, the gear train produces the torque that rotates the winch's drum. The winch's cable wraps around the drum.
Assuming you've anchored the end of your winch's line to a solid object, the drum will create tension along the line as it turns. The amount of torque the motor can produce coupled with the line's strength determines how much tension the winch can create along the line before you encounter trouble. As long as the winch and line are strong enough, the force created by the winch should be enough to help you dislodge your ATV -- or haul out a buddy who's stuck in the mud.
The winch's torque and line strength determine how much weight the winch can pull. For example, an ATV winch with a powerful motor and strong line can pull 3,000 pounds (approximately 1,361 kilograms) or more. That should provide more than enough power for sticky situations -- most ATVs weigh between 500 and 600 pounds (226.8 to 272.2 kilograms).
If you're using your ATV's winch to help someone else free another vehicle, remember to set your ATV's brakes and block the wheels. You'll need to reduce the chance that your ATV will move toward the stuck vehicle. Establish a strong anchor point with as direct a line to the stuck vehicle as you can manage.