OAuth 1.0/2.0 are a set of protocols and standards allowing applications to identify users and get access to their data using existing profiles. OAuth is mostly focused around authorization with claims (which are just key-value pairs) and authentication was an afterthought.
OpenID is another standard designed to let people authenticate across the web, launched with a lot of hype in the early web 2.0 days but never took off. OpenID Connect (OIDC) is a new standard based on OAuth 2 + OpenID to provide both authentication and authorization in a single flow.
OIDC/OAuth is all based on tokens, which are JWTs containing a bunch of claims that can be validated against the server that issued them. There are ID tokens (for the user info) and Access tokens (for accessing an API on behalf of that user), but some services like social logins don't provide any access tokens. Other providers might have rate limits, or dont have fine-grained permissions, or you maybe you have completely internal APIs that you need tokens for.
Also this video is a great in-depth walkthrough: https://www.youtube.com/watch?v=996OiexHze0