A sash is an assembly of stiles and rails with glass that form the stationary or operating section of the window. It fits into the frame. Double Hung sash also contain check rails. The operating and/or stationary portion of the window unit that is separate from the frame. The sash consists of the following parts:
1. STILES - Vertical sash members.
2. RAILS - Horizontal sash members.
3. CHECK RAILS - Horizontal sash members that meet, as in double hung units. These could also be vertical check stiles, as in the glider or patio door.
4. BARS - Divisional members extending from rail to rail or from stile to stile in an authentic divided lite unit.
5. MUNTINS - Divisional members extending from a bar to a rail or stile or another bar.