The Dire is a faction in Dota 2. Its hero base revolves around Darkness and Evil, as opposed to the Radiant's Light and Justice. Most of the heroes from the Dire have backgrounds that imply or show their darker sides.
In Dota Allstars, the Dire is known as the Scourge, in reference to the Scourge from the actual game which Dota was created in (Warcraft III).
On the Map, the Dire side is located in the top right-hand corner. Its half of the map has darkened land, skeletal towers and dead trees.