This is the type of Saskatoon windows that is composed to two wooden frames that are placed over a vertical frame that has two tracks. Each frame can manage to hold one to two panes of glass. Casement windows open outward by cranking a handle and provide a great unobstructed view to the outside as well as superior ventilation. Replacement vinyl casement windows can open to the left or right depending on your preference. Awning windows open outward from the bottom up. They are operated by cranking a handle that pushes the bottom of the sash out, allowing excellent ventilation while keeping rain water away. Hopper windows swing into the room from the top edge of the sash. An awning window is designed so the bottom of the sash will swing outward from the home when opened. Hoppers, on the other hand, are designed so that the top of the sash will swing inward from the wall when opened.