Ad an expat/immigrant, I'll tell you my personal working definition, based only on my experience:
An immigrant is one who moves from a poorer country to a richer country. An expat is one who mixes from a richer country to a poorer country.
One cool feature of my definition is that it explains a lot of the cultural subtleties in comparing these groups: how immigrants adopt the local ways much more than expats do (expats retain that touch of superiority) etc etc
On average, every situation is different, this is just my general rule of thumb pattern I've observed.
An immigrant is one who moves from a poorer country to a richer country. An expat is one who mixes from a richer country to a poorer country.
One cool feature of my definition is that it explains a lot of the cultural subtleties in comparing these groups: how immigrants adopt the local ways much more than expats do (expats retain that touch of superiority) etc etc
On average, every situation is different, this is just my general rule of thumb pattern I've observed.