A sprocket[1] or sprocket-wheel[2] is a profiled wheel with the teeth, 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 is distinguished from a equipment in that chain sprocket Sprockets are never meshed together straight, and differs from a pulley for the reason that sprockets have teeth and pulleys are easy.
Sprockets are found in bicycles, motorcycles, cars, tracked vehicles, and other machinery either to transmit rotary movement between two shafts where gears are unsuitable or even to impart linear motion to a track, tape etc. Perhaps the most typical form of sprocket may be within the bicycle, where the pedal shaft carries a large sprocket-wheel, which drives a chain, which, in turn, drives a small sprocket on the axle of the rear wheel. Early automobiles had been also largely driven by sprocket and chain mechanism, a practice largely copied from bicycles.
Sprockets are of varied designs, no more than efficiency being claimed for each by the originator. Sprockets typically don’t have a flange. Some sprockets used in combination with timing belts possess flanges to keep the timing belt centered. Sprockets and chains are also utilized for power transmission in one shaft to some other where slippage isn’t admissible, sprocket chains being used instead of belts or ropes and sprocket-wheels rather than pulleys. They may be run at high speed plus some 
kinds of chain are so constructed concerning be noiseless actually at high speed.