Which AWS service helps manage user permissions across multiple accounts?

AWS Single Sign-On (SSO) is a service designed specifically to manage user permissions and access across multiple AWS accounts and applications. It streamlines the process by allowing users to log in once and gain access to all assigned resources without needing to remember multiple credentials.

Through AWS SSO, administrators can centrally manage permissions and access levels for AWS accounts, giving them the ability to assign roles and customize user access easily. This is particularly beneficial in environments where organizations utilize multiple AWS accounts to improve security and manage workloads effectively. The integration with AWS Organizations further enhances its capability to enforce and audit user permissions seamlessly across the different accounts.

In contrast, AWS WAF is primarily used for web application security; it helps protect applications from common web exploits. AWS AppSync facilitates the development of GraphQL APIs, while Amazon Mobile Analytics (now part of Amazon Pinpoint) focuses on user engagement and mobile application analytics. These services do not specifically address the need for managing user permissions across multiple AWS accounts.