OAuth 2.0 specifies four grant types. This article only discusses the Authorization Code grant type and the Client Credentials grant type, as these are the most common types. We give a brief overview of these grants to illustrate their most common use case. Terms and definitions explains some OAuth 2.0 terms in more detail.
All supported OAuth 2.0 grant types and OIDC flows are listed in the overview table on OAuth 2.0 and OpenID Connect (OIDC) overview.