A mobile app needs to let users register and sign in with email/password, and also support social logins (Google, Apple). Which AWS service provides this managed user directory and authentication?
A) AWS IAM users.
B) Amazon Cognito User Pools.
C) AWS Directory Service for on-premises AD.
D) AWS Single Sign-On for internal employees.
Correct Answer: B
Explanation: Amazon Cognito User Pools provide a managed user directory with sign-up/sign-in, password policies, and federation with social and enterprise identity providers — designed for application end users. (A) IAM users are for AWS account access and don’t scale to millions of consumers. (C) is for on-premises AD integration. (D) targets workforce SSO.