How are links between notes stored in Obsidian

Basement
2

I’m not sure what you mean by (1). Do you have an example?

Re: (2): no, Obsidian has no link types (except for maybe the difference between backlinks and outgoing links). It has been requested:

Add support for link types

And the Juggl plugin provides a different graph view which I think allows for additional link metadata. However, I don’t think Juggl’s information is stored within the notes at all. (I could be wrong.)

Juggl (Out now! 1.0.1): A completely interactive, stylable and expandable graph view plugin!