Just like your motorcycle, you can either steer by leaning, or by countersteering, or a little of both. There are schools of thought on this. For most folks, it never matters. For hardcore racers, either on the street or on the dirt, going around corners fast can be a race-winner.
Counter-steering keeps the bike a little more "under" you, and may be safer under certain low-traction conditions.
Out on the dirt, this may keep you from "high siding" in a hard turn, as the bike will slide out rather than tossing you into the puckerbushes.