Initially RealCADD will open with a new Plan – "Untitled 1" – which will be displayed at the bottom of the Window menu. As more drawings are opened, they will add to the list. To move from one to another, simply click the one you want. The current drawing will be ticked.
This little pallet, shown to the right, simply displays the current position of the mouse with relevance to the zero point of your drawing which by default is the top left hand corner – but you can change this – see Preferences >> Display.
It can be useful when drawing an object, to know where you are on the drawing. Or when trying to decide which way you drew an object, which is the start point of a line etc. – by comparing the mouse position with the Edit pallet data.
In the Carbon version it's not very obvious how to move the pallet – you have to grab it by the tiny black triangle in the top left-hand corner.
To close the pallet, click the button on the left of it, or deselect it in the Window menu.