In aviation, a crosswind landing is a landing maneuver in which a significant component of the prevailing wind is perpendicular to the runway center line. Aircraft in flight are subject to the direction of the winds in which the aircraft is operating. For example, an aircraft in flight that is pointed directly north along its longitudinal axis will, generally, fly in that northerly direction.
However, if there is a west wind, the actual track of the aircraft will be slightly to the east of north. If the aircraft was landing north on a north-south runway, it would need to compensate for this easterly drift caused by the west crosswind.