Input Devices: A peripheral device that is used for entering data and instructions into the computer is known as Input device. Commonly used input devices are keyboard, mouse & touchpad. Computer may have some other i/o devices like web camera, microphone, touch screen, joystick, scanner & light pen.
Keyboard: Keyboard is input device which is used for entering data & instruction like letters, texts, a number, symbols & commands. It looks like a typewriter which contains a number of keys marked with alphabets, numbers & some other characters. Standard keyboard has 104 keys. Multimedia keyboard has more than 104 keys. Computer understands only binary codes, so when you press a key on the keyboard, the keyboard generates the related binary code & sends to the computer. Eg:- When we press an alphabet key "A", a keyboard generates binary code '01000001'.
Alphabet Keys: Alphabet keys are labelled with A to Z & punctuation symbols. The alphabet keys are used to enter alphabet & punctuation marks. We can enter capital alphabets(A to Z) using alphabet keys.
Numeric keys: Numeric keys are labelled with numbers from 0 to 9 & mathematical symbols +, -,*,/,. . The numeric keys are used for entering numbers & mathematical symbols.
Cursor movement keys: Cursor movement keys are labelled with arrows signs. They are used to move the cursor to the specified directions. The cursor movement keys are also known as arrow keys.
Function Keys: Function keys are labelled as F1,F2,F3, till F12. The function keys are used to enter commands.
Special purpose keys: Special purpose keys are shift, enter, ctrl, alt & del. A standard computer keyboard contains 104 keys. A multimedia computer keyboard has more than 104 keys.
Mouse: In GUI environment, we can input data & instruction into the computer which are seen on the window with the help of mouse. We can apply commands or open disk drives, files or folders by using a computer mouse.
Mouse is a small hand held input device that looks like a mouse. It is used for selecting file, folder & icon on a desktop or command on a menu. It is also used for drawing lines curves & freehand shapes.
It consists of plastic casing with a flat bottom & has two or three buttons on the top of casing. The middle button may be the scrolling button. On the flat surface of a mouse there may be a ball projected outside from a hole or loser projection hole. The left button of the mouse works like the enter key & right button displays the control menu. When we move a computer on the mouse pad, the mouse pointer on the screen moves accordingly. We can point out the command, file or folders or other items on the screen & select it by clicking the left mouse buttons. Since it points file, folder, command or items on the screen, it is also called a pointing device.
Touch Pad: A touch pad is a touch sensitive pad. It is used instead of mouse in laptop computers. It has two buttons which work like mouse left & right buttons. When we move our finger touching the pad, it moves the mouse pointer on the screen. So, we can select file, folder or other items on the desktop & input necessary commands.
Joystick: A joystick is an input device. It is specially used in playing games in computer. It controls the movement of cursor & allow us to select options or facilities of games. It is like a stick having one or more push buttons. The push buttons of the joystick are called triggers. The stick of joystick can be moved in any direction or angle &controls the movement of a mouse pointer.
Microphone: A microphone(also known as mic or mike) is an input device used for entering audio , sound or voice in a computer. The input sound or voice can be saved in a computer as a sound file. Nowadays michrophone is used to input texts or commands.
Web Cam: A web cam or web camera is an input device which captures pictures or videos & transfers into the computer as digital image or videos file. It is used for video chatting programs like Viber, messenger, Facebook, Skype,etc.
Scanner: Scanner is an input device that converts text (hand written or printed one) or pictures as digital image & transfer to the computer. These types of image files can be modified or edited using software like Adobe Photoshop, CorelDraw,etc.
It works like a photocopy machine. It has 2 components. First one illuminates the text or pictures & captures the optical images. Second one converts optical image into digital format & transfer to computer.
There are 2 types of Scanners
Alphabet Keys: Alphabet keys are labelled with A to Z & punctuation symbols. The alphabet keys are used to enter alphabet & punctuation marks. We can enter capital alphabets(A to Z) using alphabet keys.
Numeric keys: Numeric keys are labelled with numbers from 0 to 9 & mathematical symbols +, -,*,/,. . The numeric keys are used for entering numbers & mathematical symbols.
Cursor movement keys: Cursor movement keys are labelled with arrows signs. They are used to move the cursor to the specified directions. The cursor movement keys are also known as arrow keys.
Function Keys: Function keys are labelled as F1,F2,F3, till F12. The function keys are used to enter commands.
Special purpose keys: Special purpose keys are shift, enter, ctrl, alt & del. A standard computer keyboard contains 104 keys. A multimedia computer keyboard has more than 104 keys.
Mouse: In GUI environment, we can input data & instruction into the computer which are seen on the window with the help of mouse. We can apply commands or open disk drives, files or folders by using a computer mouse.
Mouse is a small hand held input device that looks like a mouse. It is used for selecting file, folder & icon on a desktop or command on a menu. It is also used for drawing lines curves & freehand shapes.
It consists of plastic casing with a flat bottom & has two or three buttons on the top of casing. The middle button may be the scrolling button. On the flat surface of a mouse there may be a ball projected outside from a hole or loser projection hole. The left button of the mouse works like the enter key & right button displays the control menu. When we move a computer on the mouse pad, the mouse pointer on the screen moves accordingly. We can point out the command, file or folders or other items on the screen & select it by clicking the left mouse buttons. Since it points file, folder, command or items on the screen, it is also called a pointing device.
Touch Pad: A touch pad is a touch sensitive pad. It is used instead of mouse in laptop computers. It has two buttons which work like mouse left & right buttons. When we move our finger touching the pad, it moves the mouse pointer on the screen. So, we can select file, folder or other items on the desktop & input necessary commands.
Joystick: A joystick is an input device. It is specially used in playing games in computer. It controls the movement of cursor & allow us to select options or facilities of games. It is like a stick having one or more push buttons. The push buttons of the joystick are called triggers. The stick of joystick can be moved in any direction or angle &controls the movement of a mouse pointer.
Microphone: A microphone(also known as mic or mike) is an input device used for entering audio , sound or voice in a computer. The input sound or voice can be saved in a computer as a sound file. Nowadays michrophone is used to input texts or commands.
Web Cam: A web cam or web camera is an input device which captures pictures or videos & transfers into the computer as digital image or videos file. It is used for video chatting programs like Viber, messenger, Facebook, Skype,etc.
Scanner: Scanner is an input device that converts text (hand written or printed one) or pictures as digital image & transfer to the computer. These types of image files can be modified or edited using software like Adobe Photoshop, CorelDraw,etc.
It works like a photocopy machine. It has 2 components. First one illuminates the text or pictures & captures the optical images. Second one converts optical image into digital format & transfer to computer.
There are 2 types of Scanners
- Handheld scanner
- Flatbed scanner
