Without getting too technical, think of it like radio signals. You can't see or feel them, but they're there. Your wireless router picks a signal from an outside source (wired from your internet provider or from a wireless tower) like a radio does and translates/redirects the signal to wireless modems. Then your wireless modem is like your ears, picking up the signal and processing it in the way that it uses it.

I hope this helps a little. I'm bad at analogies :(