A screen is the root of a tree of UIControls. Controls can be added to the screen using the Children collection. The controls can be positioned using X, Y like in a canvas, or using alignment and margins as usual.

The screen starts all HandleInput/Measure/Arrange/Render traversals of the visual tree of UIControls.

Screens are not drawn automatically. Draw(TimeSpan) must be called manually to draw the screen and all contained controls. If Width and Height are not set, the screen fills the whole viewport. The screen does not limit the layout size of the child controls. - Children can be positions outside the screen area.

Per default, screens are not focus scopes (see FocusManager) because usually the 3D scene is drawn behind the screen and the screen should not "absorb" arrow key input or thumbstick/direction pad input.