Plenty of isps that provide internet over regular ethernet. But it's a ye olde telecom provider term that referred to the phone, that you also didnt own yourself. Doesn't always apply cleanly these days.
It's an old term used by telecom to refer to the phone they owned that's in the customers home. It has been used after by internet providers if they put a device in your home. If it's your own device it's not a CPE as seen from the isp perspective.
I've never heard of that before. How does that work? Your ISP would always have to have some infrastructure within 100 meters of your router then.