Computer components that can be seen or touched are known as hardware. Hardware is anything physical within the system, such as the hard disk drive, the graphics processing unit and the motherboard. All connected peripherals, such as keyboards and monitors, also fall under this category.
When a computer is stripped down, there are usually 10 or more pieces of hardware. Many of these cannot be seen or touched until the case is open and the cooling systems have been removed. These parts include the RAM, CPU, GPU, motherboard and power supply unit. Other key pieces of hardware include the hard disk drive, DVD drives, cooling fans and sound cards.