A Van de Graaf generator is an electrostatic device that generates high voltages through the transfer of electric charge from a moving belt to a large metal sphere. Invented by Robert J. Van de Graaff in the 1920s, it features a rubber belt driven by a motor, which picks up a negative charge from a metal comb at the bottom and transfers it to the sphere at the top. The sphere becomes negatively charged, creating a strong electric field, particularly at its pointed tip, where charge density is highest. This generator can produce voltages in the millions of volts and is used in experiments such as creating lightning, powering X-ray tubes, and accelerating particles. Understanding its operation is essential for applications in physics and engineering.