Hi @suleiry m thanks for posting in the community! That's a great question pages allow you to have different diagrams on different pages in the same document. 

Whereas layers allow you to add an overlay of information or diagram on top of what already exists on a page. You can use Layers to build levels of a system show different phases of a process and illustrate alternative states of a design. This Help Center article has some information about this feature. 

If you're creating a button to navigate to a different page within the same document you can add a link to the shape you are using as a button. Once the link is added you will be navigated to the specified page when clicking that shape (for example from page 4 to page 2). 

I hope this helps. Feel free to let me know if you have any questions about these features!