Each setting has a tooltip if you hover over it explaining what it does.
Press 'ESC' to terminate erosion / simulation and continue to the next Node.
All nodes can be connected. Meaning no node has any particular data type.
Output Nodes (Image and Vertex) when connected to the Erosion Node,
will give more options for which layers to convert to images. This is done for convinience,
so that the user does not have to connect multiple outputs.
More on this here.
Make sure to select 'Fake User' (looks like a Shield Icon) to save the node tree, otherwise
it might get lost.
More info here
Do not chage Node names and labels, this can possibly break the script.