Seven Components of a Computer
Motherboard: The spine of the computer, everything connects to it. 

Power Supply unit (PSU): Provides electricity like the heart delivers blood. 
CPU: It does all the calculations (=Computing) for the computer. The brain of the computer.
RAM: Random Access Memory: The short-term memory of the computer it helps speeding up the processes from the CPU.
Hard Drive: HDD: A magnetic disk that holds all the information of the computer. It is its long term memory.
Video Card: displays images on your screen. (approximately your visual system)
CD Rom Drive: Replaced the floppy. A floppy holds 1.44 MB. A CD holds 700 MB (Approximately 80 minutes of Music (Audio)). A single layer DVD holds 4.7 GB of information, and a dual layer DVD holds in general 8.5 GB.