120v Receptacles – These are easy to identify and come in a variety of colors. 120v plugs have three slots for connecting plugs – wider for neutral, narrower for hot and arched for ground
120/240v Receptacles – These have 4 slots that provide both 124v and 240v power – two for hot, one neutral and a ground
240v Receptacles – Unlike other 3-pronged receptacles, these have a grounding slot and 2 hot slots, which prevent other devices being plugged in and ensure adequate amperage
GFCI – A Ground-Fault Circuit Interrupter or GFCI outlet is preferred for wet areas, since it reduces the risk of electrocution