Hardware devices are the physical components of computers and related systems. They form the backbone of any IT infrastructure and can be categorized into several types based on their function.All of a computer system’s parts are powered by a power source. Typically, a power cord is used to connect a computer tower to an electrical outlet. By turning off the computer, unplugging and separating the power supply cord, or trying a different cord or socket, a technician can diagnose the power supply.