What does a 120V plug look like?

115 and 120 volt receptacles or outlets are the normal outlets that you plug everyday items into. It has the two slit lookings things on either side and usually a third hole for the ground.
Since I cannot include a mini pic may I suggest you take a look at any electrical wall outlet (ac recepticle) found in your home that you plug appliances or a lamps into. This rectangular recepticle is normally covered with a plastic plate for beauty and protection. It is made to receive a plug from another appliance in order to be powered by electric current. There are two verticle slots side by side above and a round hole slot just under if a ground is included in the recepticle. The verticle slot(shorter slot) to the right is considered HOT(Voltage applied) and the one to the left is considered COMMON (return). The Plug connects into the Recepticle and makes a good electrical connection between the house wiring and the appliance. Normal voltage supplied here in the USA is 60 cycle 110-120 volts AC(alternating current). Standard Plugs in this voltage range may be called 110, 115, or 120 vac. There are 240 plugs available for higher current and power needs such as Air Conditioners. They come in a variety of configerations so that you must match the plug to the recepticle. Some have slanted and some straight verticle prongs but all are more massive in construction.