Input devices are our way of interacting with the computer and include a mouse, keyboard, microphone, joystick, etc.
Output devices are things like the display, monitor, speakers, etc.
The memory unit is the place that information is temporarily stored for the CPU to use. The storage can be a hard disk or removable media such as zip or floppy disk. This is where big programs are stored to be used by the computer. The CPU is the central processing unit. It is the brain of the computer and coordinates all the operations of the other components.