Every time you run a notebook, you are spinning up a container resource which contains an "image", which is a prebuilt environment with all the libraries and settings your team needs for reproducible data science. When you spin up a container, you lock in these runtime settings (image and container resource).
These options must be selected for every notebook you create.
These options can easily be edited for every notebook by clicking on the settings icon at the top of the the notebook editor. However, once a notebook container is running, you cannot change the resource settings without stopping the container.
Create Notebook modal with Runtime settings highlighted
You can learn more about starting up containers in the Runtime Management section of this Documentation.
You can learn more about our Resource Settings in our Container Resources documentation.
You can learn more about Images in our Images documentation.