The Components Of A Computer

A computer consists of a variety of hardware components that work together with
software to perform calculations, organize data, and communicate with other
computers.
These hardware components include input devices, output devices, a system unit,
storage devices, and communications devices. Figure 1 -3 shows some common
computer hardware components.
 

Input Devices
An input device is any hardware component that allows a user to enter data and
instructions into a computer. Six commonly used input devices are the keyboard,
mouse, microphone, scanner, digital camera, and PC camera.
A computer keyboard contains keys that allow you to type letters of the alphabet,
numbers, spaces, punctuation marks, and other symbols. A computer keyboard also
contains other keys that allow you to enter data and instructions into the computer.
A mouse is a small handheld device that contains at least one button. The mouse
controls the movement of a symbol on the screen called a pointer. For example, as
you move the mouse across a flat surface, the pointer on the screen also moves.
With the mouse, you can make choices, initiate a process, and select objects.

A microphone allows a user to speak to the computer to enter data and instructions
into the computer. A scanner reads printed text and pictures and then translates the
results into a form the computer can use. For example, you can scan a picture, and
then include the picture when creating a brochure.
With a digital camera, you can take pictures and transfer the photo graphed image to
the computer, in stead of storing the images on traditional film. A PC camera is a
digital video camera attached to a computer. A PC camera allows home users to
create a movie and take digital still photographs on their computer. With a PC
camera, you also can have a video telephone call — where someone can see you
while communicating with you.

Output Devices

An output device is any hardware component that can convey information to a user.
Three commonly used output devices are a printer, a monitor, and speakers (see
Figure 1-3 on the previous page).
A printer produces text and graphics on a physical medium such as paper or
transparency film. A monitor, which looks like a television screen, displays text,
graphics, and video information. Speakers allow you to hear music, voice, and other
sounds generated by the computer.