Just the facts, ma'am.
We are not dealing in the symbolic or the metaphorical here, only writing that is factually-presented. Just the straight-up lowdown. You'll see literal language most often in journalism, news reportage, and history (though, of course, just because information is presented in a literal, factual way, that doesn't mean it's necessarily true or objective).
For some thoughts on how literal and figurative language can work together, see our discussion of clock imagery in Ray Bradbury's "Something Wicked this Way Comes," or our analysis of the title of The Hunger Games.