Introduction to Identity on ASP.NET Core | Seed User Role | Entity Framework Core | Part-1

ASP.NET Core Identity:

Is an API that supports user interface (UI) login functionality.
Manages users, passwords, profile data, roles, claims, tokens, email confirmation, and more.
Users can create an account with the login information stored in Identity or they can use an external login provider. Supported external login providers include Facebook, Google, Microsoft Account, and Twitter.

For information on how to globally require all users to be authenticated, see Require authenticated users.

The Identity source code is available on GitHub. Scaffold Identity and view the generated files to review the template interaction with Identity.

Identity is typically configured using a SQL Server database to store user names, passwords, and profile data. Alternatively, another persistent store can be used, for example, Azure Table Storage.

In this topic, you learn how to use Identity to register, log in, and log out a user. Note: the templates treat username and email as the same for users. For more detailed instructions about creating apps that use Identity, see Next Steps.

Microsoft identity platform is:

An evolution of the Azure Active Directory (Azure AD) developer platform.
An alternative identity solution for authentication and authorization in ASP.NET Core apps.
Not related to ASP.NET Core Identity.
ASP.NET Core Identity adds user interface (UI) login functionality to ASP.NET Core web apps. To secure web APIs and SPAs, use one of the following:

Azure Active Directory
Azure Active Directory B2C (Azure AD B2C)
IdentityServer4
IdentityServer4 is an OpenID Connect and OAuth 2.0 framework for ASP.NET Core. IdentityServer4 enables the following security features:

Authentication as a Service (AaaS)
Single sign-on/off (SSO) over multiple application types
Access control for APIs