In WPF, any of the windows can be designated as child windows. A child window is like any other window but it gets minimized or closed when the parent is minimized or closed respectively. This type of window is called modeless dialog. To make a window a child of another window, the ‘Owner’ property of the child window has to be set as the parent window but only after the parent window is shown. Child windows of a window can be enumerated using the ‘OwnedWindows’ read-only property.