Studs are the main vertical members or uprights in the framing system and must carry all of the gravity loads to the bottom of the walls. These gravity forces are large in the lower storeys. As well, the studs on external walls resist the lateral wind forces by bending. The studs span between the top wall plate and the bottom wall plate and are generally one storey in height. Studs serve as a nailing base for all wall sheeting and support the upper floor platforms, which provide the lateral strength along a wall. Lateral restraint may also be offered in the plane of the wall by noggings or cladding.

WIKIPEDIA ENTRY FOR WALL STUD