Windows are frames that contain programs and files. They have title bars, toolbars, navigation panes, search boxes, and other common elements. Windows can be manipulated in several ways, including minimizing to the taskbar, maximizing to fill the screen, restoring to a previous size, moving, resizing, snapping to edges of the screen, switching between windows, and automatically tiling or cascading multiple windows. Proper use of windows is essential for effective multitasking on a computer using the Windows operating system.