1. The component that displays output
Output device
It is a hardware device which presents the information from inside the computer in a human readable format. The output is displayed on both a visual device like monitor and printers, or on a graphical device like plotter.
Types of monitors include monochrome and colored.
Monochrome monitor use only two colors – one for the screen ( also referred to as background ) and other for the information being displayed ( also referred to as foreground ).
Colored monitors display data using combination of three colors - red, green, and blue. This monitor utilizes red, blue and green phosphors which are placed adjacent to each other.
2. The component that processes data
CPU
The central processing unit or CPU is responsible for processing of the data. The computer program instructs the CPU to perform a given task. It consists of three parts – arithmetic unit to process mathematical computations; control unit to interpret the program instructions; and the instruction decoding unit which converts programs into machine instructions.
3. The component that is used to enter text !
keyboard
Input device is a hardware device which is used by humans to enter data in the computer.
Types of input devices are keyboard, mouse, scanner, joystick and the like.
Humans can interact with computers through the keyboard. It provides the only entry for text input.
Earlier keyboard consist of buttons for alphabets and numerals and special character. Modern keyboards consist of more buttons for shortcut to email. Also, buttons also serve dual purpose of a special key and control volume level when used in combination with other shift key.
4. The component you use to point to items on the screen
mouse
Another input device which is used as pointing device is the mouse.
Mouse is used to point to the screen. Earlier, mouse was connected through a wire to the computer. Modern mouse are non-wired with automatic connection.