A Simple Computer and Program

I said on my last post that I was working on my computers merit badge with my grandfather. Today he helped me make these diagrams of a simple computer (above) and a simple computer program (below). The computer diagram above includes a lot of the parts of a computer. He also told me that the part where you see "Arithmetic Unit" is the part that does all of the math in a computer. I know that software is also part of the computer. Grandpa said that the control held the soft ware. The diagram below is a little harder to understand for me. But I think it shows how an application is run inside a computer.