Window Ratio
Used when configuring multi-part windows, the window ratio tells you what proportion each part is. For example, a 3-lite casement window has 3 horizontal sections, and the left and right sections can be the same size as the middle, or the left and right can be smaller. A window ratio of "1/3, 1/3, 1/3" would have 3 sections that are the same size, while a window ratio of "1/4, 1/2, 1/4" would have smaller left and right sides.