A major component of a sliding glass door, consisting of a light of glass in a frame installed within the main (or outer) frame of the door. A panel may be sliding or fixed.

A picture window that does not move or operate.

A position or measurement that is truly and exactly vertical, 90° from a level surface.

Area below the nailing hem that the buttlock locks into.

Describes the design of the panel (Clapboard, Dutch lap, Triple 3, etc.)