The keyboard is one of the first peripherals which is used as a input device of computer. It is the primary input device for entering text and numbers to the computer. A standard keyboard includes about 100 to 104 keys which send a different signal to the CPU.
Layout of a standard keyboard
Keyboards has different styles. Different models have different size and shape although IBM enhanced keyboard has a common layout. IBM keyboard has about 101 keys according to standard US layout which are arranged in five different groups.
- Alphanumeric keys
- Modifier keys
- Numeric keys
- Function keys
- Cursor-movement keys
Alphanumeric keys on a keyboard arranged the same way on almost every keyboard which look like typewriter’s keys. Alphanumeric keys include all letters, numbers, special characters as well as four keys of special functions that is TAB, CAPS LOCK, BACK-SPACE and ENTER.
Modifier keys can modify the input of other keys. The SHIFT, ALT and CTRL keys are called modifier keys. Basically, you are changing the input of other keys in some way if you press and hold on a modifier keys.
Numeric keys are located on the right side of the keyboard which looks like a calculator’s keypad. It includes 10 digits, mathematical operators and a NUM LOCK key. When the num lock is deactivated, these key performs cursor movement controls and other functions.
The functions keys are usually arranged in a row along the top of the keyboard. They are labeled from F1 to F12 which allow you to input commands without typing long strings of characters. Each function keys purpose depends on the program you are using.
Almost all standard keyboard have a set of cursor movement keys that allow you to move the cursor without using mouse. The mark on the screen which indicates the placement of new character you entered is called cursor or insertion point. Cursor movement keys will help you to move this blinking vertical line without mouse.