[Tagbert]

“Trash compactor”

It is an in-cabinet trash can with a mechanism to compress the trash when you push the button. I don’t know how common they really are. I’ve only know a few people with them. I could see where they might be more popular in apartments where you can’t easily take your trash to an outside trash can. They do require special, heavy-duty trash bags to handle the pressure.

[DennisP]

What I'm talking about is an electric grinder that that sink drains into. Lots of people have them in the US.

[Terr_]

I've always enjoyed the pun in the branding of "The InSinkErator."

[Tagbert]

Ah, we mostly call that a garbage disposal. They are very common.

[nsvd]

Yes, the grandparent comment you're replying to also called them garbage disposal.