This is over simplified, but their are four basic parts to computer hardware. They are input, output, storage, and the Math/logic unit. How can we relate to these four areas with our own body? We are a humanoid computer so to speak.
Input devices can be the parts of our bodies that use the senses such as touch, taste, smell, seeing, and hearing. So you could say that your hands, tongue, nose, eyes, and ears are respectively input devices.
Output devices can be your skin, the body and sign language, your mouth for talking and singing, parts of your body that do waste discharging of fluids, gases, and solids. Even the growth of hair could be considered output.
The math/logic unit aka cpu could be your brain. with your brain you make decisions or what is sometimes called logic. you also use your brain to add, subtract, multiply, and divide or do the math functions. The brain is also the organizer and controller of everything.
Lastly is storage. You whole body stores for you but, Normally we would think of the brain as the largest data storage area of the body for data. The brain does input (when you try to put aways thoughts for later use and output when you want to remember things.
This was just a quickie introduction of the concepts. We will get more into the details later. One step at a time.