Basic Terminology in Transmission system

gear:  a gear is a set of toothed wheels that work together to determine or alter the relation between the speed of a vehicle's engine and the speed of its wheels; it is also the term used to describe each of the gears a driver can select, which is in fact a ratio of the selected gears on the input and output shafts.

gear ratio: the ratio between the rates at which the input and output of a set of gears rotate

clutch: a mechanism for connecting and disconnecting a vehicle's engine from its transmission system

transmission: a mechanism for transmitting power from a vehicle's engine (or motor) to its wheels

shift lever: a control lever which the driver uses to manage the current gear (or gear range) of a vehicle's transmission

H pattern: an arrangement of gears, usually designated on the shift lever knob, where in the gears are arranged in a series of parallel rows, reminiscent of an "H" with extra legs