The difference between domains, domain models, object models and domain objects

The world is a staggeringly complex place. Even relatively simple-seeming things like restaurants involve way more complexity than could be accurately captured in a software system. So instead of coding to a domain, we have to code to a domain model.For me, a domain model is a separate thing from any particular code or piece of software. If I come up with a domain model for something to do with restaurants, I could express my domain model on a piece of paper if I wanted to (or just inside my head). My domain model is a standalone conceptual entity, regardless of whether I actually end up writing any software based on it or not.