Computer hardware describes the physical components that make up a personal computer. Operating systems and many software applications can be installed on hardware in order to perform the operator’s desired functions. Most personal computers consist of a chassis in a tower shape, a desktop, all of which contain hardware components.
The main component inside the case of the computer is the motherboard. It is a large rectangular board with incorporated circuits that connect things to the computer, such as the CPU, the RAM, the disk drives, and other peripherals connected through the ports or the expansion slots. There are several components that attach directly to the motherboard: the CPU, which performs calculations and functions; the chip set, which mediates communication between the CPU and the rest of the computer; the Random Access Memory, which stores all open applications; the Basic Input Output System, which deals with power management and drivers; and the internal and external buses, which connect the CPU to peripherals, components, and expansion cards.
The power supply unit is a vital component to the computer. It converts alternating current electric power to low-voltage power for the internal components. Some power supplies have a switch to change between 230 V and 115 V while others have automatic sensors that switch input voltage automatically. Most computers have a type of power supply unit called a switch mode power supply, which regulates direct current power at the voltages required by the motherboard.
Removable media devices are also examples of computer hardware. Many of them are used for computer storage. A CD is the most common type of removable media; a DVD is a similar device except that it holds up to 12 times more information. A Blu-ray disc is an upgraded version of CDs and DVDs. It is a high-density optical disc format for data and high-definition video. This new device can store up to 70 times the information that a CD can. A floppy disk is an outdated storage device that has a thin disk of a flexible magnetic storage medium. An Iomega Zip drive is also an outdated removable device used for storage. A USB flash drive is a flash memory data storage device designed with a USB interface, typically small, lightweight, removable, and rewritable. Their capacities to store information vary from less than CDs to more than Blu-ray discs. Examples of secondary storage devices include hard disks and RAID array controllers.
Other hardware components of a computer include sound cards and input and output peripherals. Sound cards enable the computer to deliver sound to external audio devices, as well as accept input from a microphone. The majority of today’s computers have sound cards built-in to the motherboard; however, it is common for a user to install a separate sound card as an upgrade. Input and output peripherals are usually housed externally to the main computer chassis. Common examples of input devices include keyboards, a mouse, a trackball, and touch-screens. Gaming devices such as joysticks and gamepads are also in this category, as are image scanners and webcams. Examples of output devices are printers, speakers, headphones, and monitors.