tyria?

i just realised. ive been playing this game for 32 months and i dont even know where its set
what is tyria? is it the whole world of GW or is it just the prophecies campaign?
when NPCs refer to factions they say Cantha and when they refer to nightfall they say Elona, but when referring to both prophecies and the entire world they say simply, Tyria.
so which is it? the world or prophecies?

Tyria is a continent, as well as the whole world.
Just to confuse us all ^_^
(It'd be like there's a place on this planet called 'Earth'.)

From Wiki: Tyria