input devices

What is an input device?

An input device is any hardware component that is used to enter data and instructions into a computer system.

Examples and explanations of each input device:

-Keyboard

• used to enter text , numbers , special symbols and other commands into a computer by pressing buttons

• most keyboards have numbers , letters , symbols and arrow keys

Difference between

Wired keyboards and wireless keyboards

Wired keyboards are connected to the motherboard via USB cable whereas wireless keyboards communicate with the computer via Radio Frequency receiver

Laptops have integrated keyboards but , like tablets they can have external keyboards attached via USB.

Where are keyboards used?

At home, at school and in all places of work

-Mouse

• pointing device used to move and control and pointer cursor on a computer screen.

•may be wired or wireless → same as a keyboard

•a typical mouse has 2 buttons ( L & R ) and a scroll wheel

Basic operations of a mouse:

“Click” : pressing and releasing the mouse once , used to select a file or folder or open a menu

“Right-click” : pressing and releasing the right button once , used to open up a pop-up menu with different actions

“Double-click” : pressing and releasing the left button of the mouse twice rapidly , start a program or to open files/folders.

“Dragging” : Moving the mouse while holding down the left button , icon may be moved on the computer screen by selecting it and dragging it to a new location. Same for files to be moved in folders

“Scroll wheel” : found between the left and the right buttons , rolled with the finger to move up and down a page or document.

-Touchpad

• a pointing device found on laptop computers.

• made up of flat and touch sensitive surface on which user slides a finger to move the cursor on the screen.

• works by sensing the user’s finger movement and downward pressure.

• alternative to the mouse

• can be used on the move where there is not enough space to accommodate a mouse

-Joystick

• cursor control device mainly used for playing computer games.

• consists of a stick that pivots on base

• several push buttons , which r pressed to send signals to the computer

• also used for controlling machines

• helpful for people with movement disabilities

-Scanner

• produces a digital image of information contained in hard copies

• transfer into the computer system where it is stored as a file

• used to convert … into images that can be stored and transferred electronically

-Barcode reader

• device that can read printed barcodes (black and white lines) found on products.

• uses laser beams to capture barcodes and translates them into digital info

• widely used in supermarkets and shops

• very popular since it eliminates the possibility of human error

• very fast and reliable

More easy learning input devices are :

Web camera , Touch screen , Microphone and digital camera

-Sensors

• used to measure physical quantities (such as temperature, light, pressure and sound) and send signals to a computer processor.

• data fed into the processor is examined by a control program which decides what to do next.

• Different types of sensors are used in different applications.