Anchor behavior allows an object to retain it's position no matter the screen size/aspect ratio of the game, by clipping it's edges (Bottom, Left, Right, Top). This is most useful for UI/HUD objects that are static.

To add Anchor to an object, first open the object properties by creating a new object or by accessing the object in the Scene Object list. Select “Edit object” from the popup list. Then select “Behaviors” and click the add behavior button.