What are User Claims in IdentityServer4 API Resources vs. API Scopes

Question

I've configured an instance of IdentityServer4 and have successfully configured it as a client for an OIDC provider. I'm now trying to set it up as the OIDC provider for my application. I've followed through the quickstarts and read the documentation, but I'm struggling to find an answer to my specific question.

User claims can be specified in a couple of different places: on the API resource and on the API scopes. What is the difference between specifying a user claim on an API resource vs. on an API scope for that resource?

My understanding of the terminology is that:

• An API resource represents the API that clients will access, e.g. a "the GitHub API", my "data import API"
• An API scope represents a subset of resources within that API, to which clients can request access, e.g. repo => public and private repositories, import_job:control => start/stop/delete import jobs
• A user claim is a piece of information about the user, e.g. email => email address

It must make sense to associate user claims with an API resource and/or scope, but I can't make the mental leap to identify why and how. Please provide illustrative examples of these claims and what they represent in the contexts given above: the GitHub API (hypothetically, if there are none actually defined), and a generic batch import API.