Using built-in authentication
If you don't use a centralized, external system for your users' identity, you can use built-in authentication to allow GitHub Enterprise Server to manage accounts and perform local authentication.
Configuring built-in authentication
When you use the default authentication method, all authentication details are stored on your GitHub Enterprise Server instance.
Inviting people to use your instance
When you use built-in authentication for GitHub Enterprise Server, you can invite people by email address to create a user account on your instance.
Disabling unauthenticated sign-ups
If you're using built-in authentication for your GitHub Enterprise Server instance, you can block unauthenticated people from creating new user accounts on your instance.