A dynamo is a device that converts mechanical energy into electrical energy using the principle of electromagnetic induction. It typically consists of a rotating coil of wire within a magnetic field, which generates electricity as the coil moves. Dynamos are commonly used in various applications, including powering small machines and charging batteries. The invention of the dynamo is attributed to Michael Faraday, who discovered the principles of electromagnetic induction in the 1830s. Over time, dynamos have evolved into more advanced generators, such as alternators, which are now widely used in vehicles and power plants to produce electricity efficiently.