IT Revision

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Computer Hardware: It is a physical parts attached to a computer. For example:

Input Devices: Devices that allow the user, which may be another computer or measuring device, to give instructions or provide data to the computer system.

Keyboard: The keyboard is still one of most common methods of inputting data or instructions to a computer. The keys that allow access to a range of alphanumeric characters, special characters such as '/' or '£' and a number of commands by using the functions keys. It also provides shortcuts to specific tasks, for example by pressing the keys Ctrl/Alt/Delete together, the task manager box appears on the screen.

Mouse: A point and lick device, the mouse allows the user to communicate with the computer by replacing a cursor at a particular point on the screen. The mputer screen tasks tracks the movement of the mouse and normally displays its location on the screen as a cursor.

Scanner: This input device converts a document or photographinto a digital file that a computer can read or display. Scanners have been developed for other uses such as biometrics. Examples include iris and fingerprint scanning, where the iris or fingerprint is illuminated and photographed.

Sensors: Sensors are physical devices such as thermometers, motion sensors and microphones that send signals to the computer. These signals enable the computer to decide whether an action must be triggered. For example, if a burglar alarm is set, any signal received from the motion sensor suggests that someone is in the building and the computer triggers the alarm.

Mirophone: These record instructions from the user, or other sounds that the user wishes to collect. For those who cannot use a traditional keyboard or mouse, this is a very useful device for inputting data.

Graphics tablet: This can be used in a similar way to the keyboard by tapping on icons. It is also useful for entering data, such as handwriting or drawings of objects which cannot be captured easily in other ways. It can be hard to control if the sensitivity is set too high or low, although this can often be adjusted via the software.