Engine - Most chainsaws use a 2 cycle engine to power the cutting chain. As with other engines, chainsaw engines use spark plugs The power of the engine is transferred through a centrifugal clutch to the chainsaw chain.

Fuel - Chainsaws have typically used 2 cycle engines and thus require fuel with oil mixed into the fuel. In recent years, four stroke engines have been used in some chainsaws.

Bar - the bar of the chainsaw creates a support surface for the chain. Chainsaw bars have provisions to allow oil to flow from the oil tank to lubricate the chain and bar.

Chain - the chain is driven by the drive sprocket and it is used to cut wood by removing a piece of wood as each blade is pulled across the surface of a piece of wood.

Chain Tensioner - the chain tensioner mechanism allows for the tightening or loosening of the chain by extending or retracting the bar from the drive sprocket.

Hand Guard - in order to keep operators safe, the hand guard prevents the operators forward hand from coming in contact with the chainsaw chain near the top of the bar.

Bar Oil - Chainsaws use oil to lubricate the bar as the chain slides passes around the bar in the groove of the bar. Bar oil is kept in a reservoir on the chainsaw.

Bar Oil Reservoir - The Chainsaw bar oil or bar lube is stored in the fuel reservoir.

Bumper Spike - Sharp metal spikes near the base of the bar that help hold the chainsaw in place when cutting logs.

Control Lever - The control lever controls the chainsaw including choking the engine, starting the engine, run and start.

Throttle Trigger - The chainsaw throttle trigger controls the speed of the engine.

Decompression Valve - some chainsaws utilize a valve to allow easier starting by releasing compression on the engine.