We just came from the grocery store earlier today (yup, hubby had to go to work late) and our youngest was fascinated by the barcode scanner being utilized by the sales clerk. It kept beeping (which was normal, to indicate that the product was successfully scanned) every time a product was placed in front of it, so our young boy's attention was captured. He asked if somebody was inside doing all the beeping; I couldn't help but laugh. ;)
Know what I did? I told him all that I know about how it could have made that beeping sound. No baby talk/explanations. Of course, in simpler terms, of course. No heavy techie stuffs. He seemed to understand (or got bored, lol) with my explanation, since he kept quiet after that and just watched.
A young child's mind is so precious.