What does Alex mean by incognito for external users? This was not covered unless this is misunderstood as creating a role for an external user rather than IAM user for internal.
Unless it means where you can add user sign-up and authentication to your mobile and web apps. Amazon Cognito also enables you to authenticate users through an external identity provider and provides temporary security credentials to access your app’s backend resources in AWS or any service behind Amazon API Gateway. Amazon Cognito works with external identity providers that support SAML or OpenID Connect, social identity providers (such as Facebook, Twitter, Amazon) and you can also integrate your own identity provider.