> , the component that controls a device or machine that operates in our actual physical world.

So is a an industrial factory control server embedded? It controls valves, actuators, reads sensors. It can still be a whole rack top to bottom full of high power Xeon servers.

Embedded literally means inside something. It is not a computer used on its own, say to run general purpose software, but as part of another larger system. There is no power or size requirements for that. Well and most of all it is a fuzzy term.