Where are notes stored in Microsoft OneNote?

I use the desktop app from MS OneNote for notes during my studies. Since there's a lot of notes together, here's my question: Are the notes stored exclusively in the OneDrive Cloud or locally on the hard drive of the laptop? Since my laptop has relatively little internal memory, it would make sense for me to save the notes only in the cloud.

Theoretically, only in the cloud.

I do not know how it is programmed. Maybe some files are kept locally as a cache to make them faster…