Incremental changes

Hi Everyone,
So I want to fetch all the folders and files in my root folder and the box gives us client.folder("id").get_items() method and it's good.

However, Suppose Yesterday I had 10 folders today. And I had already fetched the folder hierarchy for those 10 folders. Now today I added 2 new folders, So instead of fetching all of them again. How do I get only the 2 new folders?

FYI : I am not trying to download the contents. I only want to create a tree structure of my root folder