# Creating and Positioning an Overlay

Overlays are extensions of Modules and differ in the sense that the float above the normal page flow. They can be positioned in three different ways: By fixing them to the center of the viewport (overlay1 below), by specifying a position (overlay2), and by positioning them relative to a context element (overlay3).

Use the buttons in the example below to show and hide the three Overlay instances.

overlay1:
overlay2:
overlay3:
Align to me
Overlay #1 from Markup
This is a Overlay that was marked up in the document.
End of Overlay #1