What are OpenID scopes and claims?

Claims are specific attributes about a user. Wiki defines it as "A claim is a statement that one subject, such as a person or organization, makes about itself or another subject. For example, the statement can be about a name, group, buying preference, ethnicity, privilege, association or capability. ".

Source: Wiki

A scope is an indication by the client that it wants to access some resource, your server may allow or reject this. Oracle - Oauth Scopes

To provide an example, in your application your user may have a name, email and company name - these are your claims. That client may request access to your Admin controller of your Web API, this would be a scope. In an SSO environment, it could be some other application in its own right such as another API.

Google use scopes to control access to data transfer / analytics / ads APIs Google Oauth Docs

To be more specific than the previous answer:

scope: A scope is a space separated list of identifiers that specify what access privileges are being requested by the client application

claims: A claim is a key-value pair that contain some information, e.g. user information

For more details see - https://mannharleen.github.io/2020-03-11-id-access-tokens/#the-story-of-scopes--claims