A double hung window has two operable sashes that move up and down. The sashes slide in tracks built into the frame and are held in position by either counterweights, springs, or friction. The sashes are locked shut with a latch located where they meet in the middle. Double hung windows are associated with a more traditional aesthetic and often have simulated divided lites, or window grids installed. A double hung window that has a top sash narrower than the bottom sash is sometimes called a cottage window.