What is the primary function of the Amazon Cognito service?

The primary function of the Amazon Cognito service is to manage user authentication. Amazon Cognito provides a secure and scalable user identity and access management system that allows developers to easily manage sign-up, sign-in, and access control for web and mobile applications. It helps developers integrate authentication with social identity providers (like Google, Facebook, and Amazon) and enterprise identity providers via SAML, thereby streamlining the process of managing user accounts and ensuring secure access to applications.

By leveraging Amazon Cognito, developers can also implement features such as user pools for managing sign-up and sign-in processes, as well as federated identities for providing access to AWS resources. Thus, it plays a crucial role in enhancing the security of applications through effective user management and authentication processes.