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 where radial projections engage a chain passing over it. It really is distinguished from a gear in that sprockets are never meshed together straight, and chain sprocket differs from a pulley in that sprockets have tooth and pulleys are easy.
Sprockets are found in bicycles, motorcycles, vehicles, 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 monitor, tape etc. Perhaps the most typical form of sprocket could be within the bicycle, in which the pedal shaft carries a huge sprocket-wheel, which drives a chain, which, in turn, drives a little sprocket on the axle of the rear wheel. Early automobiles had been also largely powered by sprocket and chain mechanism, a practice mainly copied from bicycles.
Sprockets are of various designs, no more than efficiency getting claimed for every by the originator. Sprockets typically don’t 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 used for power transmission in one shaft to another where slippage isn’t admissible, sprocket chains getting used rather than belts or ropes and sprocket-wheels rather than pulleys. They can be operate at high speed and 
some kinds of chain are so built concerning be noiseless even at high speed.