tail boom
Also known as an "empennage" is the tail of the helicopter.

transmission shaft
connects the engine to the transmission

Cowling
The aerodynamic covering for the engine.

Tail Rotor Driveshaft
Provides power to the tail rotor from the transmission.

cabin doors
access to helicopter

fuselage
The body of the helicopter.

Skids
Landing gear that usually has no wheels or brakes. Helicopters can be fitted with wheels and floats

45 Degree Gearbox
Transfers power up the vertical fin to the 90 degree gearbox.

engine mount
A flexible way to attach the engine to the fuselage.

tail rotor
The tailrotor in normally linked to the main rotor via a system of driveshafts and gearboxes, so both are usually connected to the same transmission, meaning that if you turn the main rotor by hand, the tailrotor will also turn. Most helicopters have between a 3:1 to 6:1 ratio. (In the first case, every time the main rotor turns one rotation, the tail rotor makes three revolutions) For example: If the main rotor is turning at 324 RPM, then the tail rotor turns at 1944 RPM at 6:1.

tail assemby and 90 Degree Gearbox
The adjustability of the tail rotor is straightforward -- what you want is the ability to change the angle of attack on the tail rotor wings so that you can use the tail rotor to rotate the helicopter on the drive shaft's axis. The pilot has two foot pedals that control the angle of attack. These two videos let you take a look at the pedals and see how they affect the tail rotor:

mast
Connects the transmission to the rotor system

transmission
Takes power from the engine and drives both rotor systems.

Engine
Provides power to the rotor systems. This engine is a jet turbine. Smaller helicopters such as the Robinson series are powered by piston engines

Stabilizer Bar
Dampens control inputs to make smoother changes to the rotor system.

tail skid
Protects the tailboom when landing.

main rotor
A helicopter's main rotor is the most important part of the vehicle. It provides the lift that allows the helicopter to fly, as well as the control that allows the helicopter to move laterally, make turns and change altitude. .

Synchronized Elevator
A movable wing that helps stabilize the helicopter in flight.

Crosstube
The mounting tubes and connection for the skids.

swash plate
The swash plate assembly consists of two plates -- the fixed and the rotating swash plates -- shown above in blue and red, respectively.

The rotating swash plate rotates with the drive shaft (green) and the rotor's blades (gray) because of the links (purple) that connect the rotating plate to the drive shaft.

The pitch control rods (orange) allow the rotating swash plate to change the pitch of the rotor blades.

The angle of the fixed swash plate is changed by the control rods (yellow) attached to the fixed swash plate.

The fixed plate's control rods are affected by the pilot's input to the cyclic and collective controls.

The fixed and rotating swash plates are connected with a set of bearings between the two plates. These bearings allow the rotating swash plate to spin on top of the fixed swash plate.