It is a half-bridge driver. The upper and lower drive outputs have equal propagation delays. They provide active turn-on and turn off for both the low-side and the high-side transistors. Study the datasheet, and check out the application notes cited in this thread.
BTW, feel free to post in the IR2112 thread (after skimming through the existing posts of course). I'm keeping tabs on that thread, and I'm trying to make sure my answers are sufficiently generic enough to cover other mosfet drivers and related questions.