Input and Output Devices:

These devices are useful to interact with the computer. Input devices accept data and instructions from the user or from another computer system such as a computer on the Internet. Output devices return processed data to the user or to another computer system.

Input Devices: The most common devices we can find are: keyboard, Mouse, Joysticks, Scanners, Digital cameras, Microphones, Cd player.

Output Devices: The most common devices are: The monitor and the printer.

Storage:

A computer needs a place to keep program files and related data when they are not in use. The purpose of storage is to hold data permanently. In other words is the capacity of a device to hold and retain data.

Although the functions of storage and memory are similar, they work in different ways. There are three major distinctions between storage and memory.

1. There is more room in storage than in memory
   
2. Contents are retained in storage when the computer is turned off.
   
3. Storage is very slow compared to memory, but cheaper than memory.
   

There are many types of storage devices, like optical drives, removal hard drives, cd-rom drive etc.