Please clarify the Google connection.

I'm guessing that it's an official Google-built product. [1]

[1] http://support.google.com/notebooklm/answer/16179536?sjid=62...

Unlike large models such as Gemini or ChatGPT, where information is extracted from numerous web sources that may contain “hallucinations,” NotebookLM relies 100% on the sources you provide, such as PDFs, audio files, YouTube videos, Google Docs, or even articles. By working exclusively with your sources, the tolerance for hallucinations is very low.