At this point I'm almost afraid to ask but my attempts to figure it out have failed. What is a Jupyter notebook? Where is the code running? On your computer? On someone elses computer?
Jupyter is a web application that lets a user execute python code in either a local or remote "kernel" - which is just a Python process with a communication layer.
You can then do literate programming (meaning run some code and immediately see results including plots and tables) within this web interface. Basically a much fancier REPL. The code can run either locally on your machine or remotely in the aforementioned python "kernel".
Here's a quick introduction to Notebooks that I found on YouTube: https://www.youtube.com/watch?v=jZ952vChhuI