What's the actual difference between greater vs metro cities?

https://lemmy.world/post/15411189

What's the actual difference between greater vs metro cities? - Lemmy.World

I hear some cities call the larger area as metro (Vancouver) and other cities call it greater (Toronto). Is there a functional difference? Generally speaking, is one more urbanized than the other?

From my basic understanding

Greater = the area including and around a city

Metro = the parts of a community within some sort of combined local government