The device usually referred to as a charger is not really a charger but a safety plug designed to protect users from getting shocked by the power. This device, an EVSE (electrical vehicle service equipment) waits until it is plugged safely into a vehicle and can tell how much power the vehicle's charger wants before it turns on the power to the cable and the car's charger.
Three Types of Chargers
Level 2 - Level 2 chargers operate on 220 V much like a dryer or stove does in your house. Most public charge stations are level 2 and they are available forhome use. Chargers can supply current to the vehicle at many different rates depending on the service supplied to them and the current available changes the rate the vehicle will charge at, but generally vehicles will add 15 to 50 miles of range per hour of charging
Level 3 - Chargers rated as level 3 are usually public chargers designed to recharge vehicles in 20-45 minutes by using an industrial 3 phase 440V supply and they require most vehicles except the Tesla to have a different plug to recharge at this rate