Go to your house phone (if you have one) and trace the beige-ish cord (usually) from the phone to the wall, then picture that cord running underground to some kind of base station down the street then connecting from that to your local telco office.

Now picture your same home phone without thqat beige cord plugging into the wall, and instead with an internal antenna picking up a cellular signal. So it's like your cell phone you carry in your pocket or on your belt, but it's a home phone. I've never seen a tellular unit myself but I believe they're not much bigger than your normal cordless bases.

Did that answer your question sort of?