What are Input Devices
Any information or program is fed into the computer through the input devices. In other words, the devices that are used to enter any information or instructions into the computer are called Input Devices. The most commonly used Input devices are
Keyboard – This is the main method or means by which we issues commands to the computer. It is quite similar to the keys of typewriter. In addition there are some keys such as function keys, arrow keys and other special keys. A normal key board has 101 keys.
FUNCTIONS OF KEYS ON A KEY BOARD
1.Typewriter Keys – These are white-coloured keys spreading themselves in the centre of keyboard. These keys include letters, numbers and punctuation symbols. These keys are used to type data.
2. Function Keys – These keys are at the top of the keyboard labelled F1 to F12. These keys carry different functions for different software. For e.g. in DBAse to list records we use the F3 key.
3. Numeric Key Pad – This pad is placed on the right side of computer. It contains calculator like keys. It serves double purpose, when Num lock is on the numeric keys get activated when Num lock is off it performs function marked on them. For e.g. No.7 key also has home written on it.
4. Cursor Keys – These are four cursor keys to left of numeric key pad. These are used for cursor movements.
5. Caps Lock Key – When caps lock key is pressed once all the letters that we will type will come in upper case. The effect can be reversed when we press the key agin.
Shift Key – When we press shift key down and press a letter it will come in upper case. Where there are two character on a key (as on number keys), pressing shift key and the key will bring the upper letter i.e symbols like *,!,~,@,$ etc.
Enter – It is used to execute a instruction or to alert the computer that we have finished the instructions.
Tab – It is used to move cursor along preset cursor positions.
Esc – It is used to cancel or ignore the command that we have entered.
Pause – This key is used to stop the scrolling screen.
Print Screen – When we press this key, whatever is being displayed on the screen, gets printed on the printer.
Mouse – Mouse is also an input device. It is a hand-held pointing device that allows us to control the computer without having to type in instructions at the key board. The mouse is rolled across the desktop and the cursor moves across the screen it is brought to the desired location and then one its button is pressed. The desired location may be a menu or bar of a menu. It is also used with graphics. It is also used as a brush in softwares like windows to create figures directly on the screen.