What is dota?

Defense of the Ancients, commonly known as DotA, is an Aeon of Strife-style custom map created for the game Warcraft 3. Originally developed for Warcraft 3: Reign of Chaos by Eul (US West), the map was later unofficially ported into the Warcraft 3 expansion pack, The Frozen Throne. Currently, several variants of the map exist under the name of DotA.