Computer hardware refers to the physical components of a computer system. It can be broadly classified into two categories: system unit and peripherals. The system unit includes the Central Processing Unit (CPU), which is responsible for processing data, and other components such as motherboard, memory, and storage devices. The peripherals include input devices such as keyboard and mouse, output devices such as monitor and printer, and other devices such as scanners and speakers. Therefore, the correct answer is "System Unit and Peripheral".