Usually this is 0, but if you have multiple X terminals connected to the same machine, then each terminal is generally assigned a different display number. The screen number is also usually 0, but if your display has multiple screens, then each is identified by a small integer. The default geometry of each window is specified in pixels, using the following hierarchy of specifications. Missing details at each level are supplied by those below. Once displayed, the window can be resized with the mouse, but the drawing area is only resized to reflect this when the next page is started.
Resolution Depends on monitor.
Color capability Colormaps of types PseudoColor, StaticColor, GrayScale, StaticGray, and TrueColor are supported. By default, the first available colormap from one of the following lists is used. If the first available colormap type happens to match that of the default colormap of the screen, and enough colors are available therein, then that colormap is used. Otherwise, allocation of a private colormap is attempted. If this fails, the device is treated as monochrome.