The rotors are long, thin wings that spin very fast to lift the helicopter off the ground. These rotors let the helicopter hover in one place. Airplanes can't do that.
Helicopters can also take-off and land without having to use a runway or airport.
This makes the helicopter go up and down. The tail rotor keeps the helicopter pointed in one direction. Without it, the helicopter would just spin around in circles. Some helicopters can have as many as six main rotor blades, and up to five tail rotor blades. Skycam 16 has two main rotor blades and two tail rotor blades.