Game Development Dictionary
AABB is an acronym for Axis-Alligned Bounding Box. Effectively it is a cuboid which is not rotated. All of its edges are parallel to the axes it is alligned to. AABBs can be defined using just two points, a maxium point and a minimum point. The rest of the box can be worked out from these two points. AABBs can be used for collision detection and scene culling (among other things).