2. • An input device is any device
that provides input to a
computer. There are dozens of
possible input devices, but the
two most common ones are a
keyboard and mouse.
input devices are a vital
part of every computer
Some examples include
webcams, card readers, touch
3. • In computing, a keyboard is a typewriter-style
device, which uses an arrangement of buttons
or keys, to act as mechanical levers or
electronic switches. Following the decline of
punch cards and paper tape, interaction via
teleprinter-style keyboards became the main
input device for computers.
A keyboard typically has characters engraved
or printed on the keys and each press of a
key typically corresponds to a single written
symbol. However, to produce some symbols
requires pressing and holding several keys
simultaneously or in sequence. While most
keyboard keys produce letters, numbers or
signs (characters), other keys or
simultaneous key presses can produce
actions or execute computer commands.
4. A light pen is a computer input
device in the form of a light-sensitive
wand used in conjunction with a
computer's CRT display.
It allows the user to point to
displayed objects or draw on the
screen in a similar way to a
touchscreen but with greater
A light pen detects a change of
brightness of nearby screen pixels
when scanned by cathode ray
tube electron beam and
communicates the timing of this
event to the computer.
5. In computing, a mouse is a pointing
device that detects two-dimensional
motion relative to a surface. This
motion is typically translated into the
motion of a pointer on a display, which
allows for fine control of a graphical
Physically, a mouse consists of an
object held in one's hand, with one
or more buttons. Mice often also
feature other elements, such as
touch surfaces and "wheels", which
enable additional control and
6. A barcode reader (or barcode
scanner) is an electronic device for
reading printed barcodes. Like a
flatbed scanner, it consists of a light
source, a lens and a light sensor
translating optical impulses into
electric al ones.
Additionally, nearly all barcode
readers contain decoder circuitry
analyzing the barcode's image data
provided by the sensor and sending
the barcode's content to the
scanner's output port.
7. The Xbox 360 Controller is the
primary controller for Microsoft
Corporation's Xbox 360 console and
was introduced at E3 2005. The Xbox
360 controller comes in both wired
and wireless versions.
Original Xbox controllers are not
compatible with the Xbox 360.
The controller is also compatible
with PCs; the wireless version
requires a Wireless Gaming
The wireless controllers run on either
AA batteries or a rechargeable
battery pack. The wired controllers
may be connected to any of the USB
ports on the console, or to an
attached USB hub.