yes the armageddon is the end of the world. its believed to happen in 2012. from what i heard, a an asteroid similar to the one that might have killed the dinosaurs may come back to earth, creating an explosion that would wipe out all life. that would mean armageddon. the same thing actually happens in the movie as well.
Well, it wasn't the asteroid that killed off the dinosaurs, it was the debris in the sky, with the blocking out of the sun and such. --
Apocalypse equals death of all humans, and most other life. The earth, though, she'll probably out-grow the human race and recover until there's no trace of us left. There are lots of possibilities for how it will all end, nuclear holocaust, WWIII, pollution, and lots of other ways.