(Christian) Prophecy
In the Christian Bible, Daniel is placed right after the major prophets—Isaiah, Jeremiah, and Ezekiel—and right before the minor prophets. This is meant to imply that he's sort of a major prophet—or, at least, he's a really important prophet.
On the other hand, in the Jewish version of the Bible, Daniel is placed in the Writings (the "Ketuvim")—with Esther and the rest—and not in with the Prophets (the "Neviim"). It's placed towards the end and is one of the last books in the Hebrew Bible where God makes a "visual" appearance, so to speak—though he doesn't really have any speaking lines.
Part of the reason for this confusion is that the Book of Daniel's got a bit of a split personality. The first part (chapters 1-6) is all courtly legends—real sock-it-to-'em celebrations of Daniel and pals as they outwit Babylonian and Persian kings and stand up for their faith. Functionally, they're sort of like superheroes in comic books. Just like a quiet comic book reader digs the story of a mild-mannered computer-whiz by day, who secretly fights crime and kicks arrogant crime-lord butt by night, the occupied Israelites really dug the stories of faithful Jews who possessed the power to overcome their adversaries.
The second half is all visions, dreams, and prophecies, all loosely fitting under the headline of apocalyptic literature. An apocalypse, to put it super briefly, is a divine revelation concerning things to come, often focused on the "end-times." That's why we have the modern association of "apocalyptic" things being all about the end of the world, or at least, the end of the world as we know it. (The Hunger Games, anyone?)
Now, Daniel gets a reputation for being a Jewish apocalypse (its Christian colleague, the Book of Revelation, is where the term "apocalypse" comes from) because chapters 7-11 narrate five dreams that explain what's going to happen in the last days, in a super-detailed and super-epic fashion. There are specific signs, visions of the heavens, and (of course) a nice hint of resurrection at the end of days. So Daniel, as well as being the hero of his own courtly sagas, is also the messenger for a hyper-detailed prophetic vision of the end of the world.
Talk about artistic range.