According to Home Depot, a 20-amp outlet is a higher powered outlet commonly used in areas of the house where high-current electrical devices are used. Kitchens often have 20-amp outlets to power small appliances.
A 20-amp outlet is only compatible with a 20-amp circuit. The circuit's ampere rating can be found by checking the breaker box. A 20-amp outlet is identifiable by horizontal slots that cross the more typical vertical slots of a normal outlet. This kind of outlet is served by either 12-gauge or 10-gauge wiring. The thicker wiring ensures that the wires do not overheat under the higher load of a 20-amp outlet.