NotebookLM is a multi-purpose notebook with AI features. You can create notebooks, feed content, ask questions about the content, save individual answers, and much more. Additionally, it can create a podcast based on your content.
The feature is impressive if you want a primer into discussing the sources of materials or a gloss over kind of preview of the materials.
To game it to do in depth stuffs, I heard it was possible but you need to do a few things. Sadly I don't.
Still, I did try it for most new documents I receive and wanting to get an overview and I must say I'm not disappointed (even if it's very superficial in my use cases)