A sprocket[1] or sprocket-wheel[2] is a profiled wheel with tooth, or cogs,[3][4] that mesh with a chain, monitor or other perforated or indented material.[5][6] The name ‘sprocket’ applies generally to any wheel upon which radial projections engage a chain passing over it. It really is distinguished from a gear in that sprockets should never be meshed together straight, and differs from a pulley in that sprockets have the teeth and pulleys are easy.
Sprockets are used in bicycles, motorcycles, cars, tracked automobiles, and 
other machinery either to transmit rotary motion between two shafts where gears are unsuitable or to impart linear motion to a monitor, tape etc. Maybe the most typical form of sprocket may be within the bicycle, where the pedal shaft bears a sizable sprocket-wheel, which drives a chain, which, in turn, drives a small sprocket on the axle of the trunk wheel. Early automobiles had been also largely powered by sprocket and chain mechanism, a practice largely copied from bicycles.
Sprockets are of varied designs, no more than efficiency becoming claimed for every by the originator. Sprockets typically do not have a flange. Some sprockets used in combination with timing belts have flanges to keep carefully the timing belt centered. Sprockets and chains are also utilized for power transmission in one shaft to some other where slippage is not admissible, sprocket chains being used instead of belts or ropes and sprocket-wheels rather than pulleys. They can be run at high speed plus some types of chain are so built as to be noiseless also at high speed.