A gear drive drive requires two gears for operation. The two gears are spur cut, and the drive equipment receives pressure from the power output. The drive gear then transfers capacity to the driven gear.
Different Drive Systems
All drive systems require a drive gear. The drive gear is the main transfer from the power source to the driven gear. A belt from the drive equipment to the driven gear is a "belt powered" system. Another option may 
be the "chain driven" system. The "chain driven" system runs on the chain from the drive gear to the driven gear. The "gear drive" program is immediate gear-drive. The drive gear is directly meshed with the driven gear.
Common applications
Gear drives are found in transmissions, back ends and transfer situations; sometimes the drive gear will be smaller than the driven gear. Different gear ratios enable the transmission to shift to lower or more rpm speeds.
Automotive gear drive
Gear drives are used on automotive engines. A "gear drive" usually refers to the timing drive; it replaces the normal timing-chain with spur-cut gears. A equipment drive is known for the "whining sound" it emits. One's teeth of the gears mesh jointly as the gears switch with the rotation of the engine. This helps to keep the engine in time.