Do you mean the Sicilian Dragon? This? If so, the idea is a razor sharp variation where one step is a step that loses you the game. If Fischer's quotation "Chess is life," is true, then you may well be sleeping in an aquarium when the last bit of wood is pushed.
Motifs include an exchange sacrifice on the c-file (Your Rook for his or her c3 Knight, I believe), dark squared play (where neither player will give up his or her DSB unless it is an exchange, most often done when White has a Queen on d2 and Bishop on e3 and plays Bh6 to exchange for Black's fianchettoed Bishop), mutual pawnstorms, and players with weak bladders having to read a disclaimer before touching a piece.
This doesn't even begin to scratch the surface.
what is the objective of this attack and why do people use it