Layers
A layer is nothing more than a dynamic container for your contents. A layer can have text and images inside itself. It is independent as its absolute position allows you to positionate it anywhere in the page.

Create a new document and save it.

Insert --> Layer

Now you can see the layer displayed in the page. click inside it and insert an image, example.gif in this case.

Then insert another layer and type 'SOME TEXT' into it.

Positionate them somewhere in the screen and save the document.

Open the file or the example to see how it looks like.

You can use layers as you want, simply don't forget to prevent layers overlaping eachother. To do this:

Window --> Others --> Layers.

In the 'Advanced Layout' window tick 'Prevent Overlaps'. This will prevent the layers overlaping eachother and this is very useful to layout a document