You don't see them on your monitor, but you can use a small navigation tool to move your display to whatever part of the virtual desktop you choose. Windows that appear on one desktop, disappear when you move to another, only to reappear when you switch back. Usually, each desktop can have a different background. X Pixmap Early window managers used only one color for the foreground and a second for things like title bars and icons. But modern window managers let you have multicolored icons, using a format called X Pixmap.
Some window managers support other graphics file formats too.
Shape X originally supported only rectangular windows. Eventually it was extended so that windows could take any shape. Window managers with Shape break through the rectangular-only restriction. Pinnable Menus Menus normally disappear from the screen once you have made your selection. This can make things easier if you need to choose many options from the same menu.