A coupling is a device used to connect two shafts together at their ends for the purpose of transmitting power. It provides a flexible connection that can accommodate slight misalignments and helps to reduce vibrations and shocks. Couplings are commonly used in various industries such as automotive, manufacturing, and power transmission. They come in different types, including rigid couplings, flexible couplings, and fluid couplings, each designed to suit specific applications and requirements. Couplings play a crucial role in ensuring smooth and efficient power transmission between rotating machinery components.