The moveable part of the window that holds a pane of glass is the sash.

The horizontal, bottom part of the frame is the sill.

A window in which one sash slides up and down and the other sash doesn't move is considered single hung.

Single-strength glass has a thickness of approximately 3/32".

A slider window has a sash that moves back and forth as opposed to up and down.

A sloped sill is the exterior bottom part of a window that has a downward slope to allow for water runoff.

The solar heat gain coefficient measures the percentage of heat entered through glass from both direct sunlight and absorbed heat. The smaller the number, the greater the reductions of heat gain.

The vertical parts of a sash are the stiles.