What is the primary use case for Amazon SNS?

The primary use case for Amazon Simple Notification Service (SNS) is event-driven messaging. SNS is a fully managed messaging service that facilitates the sending of messages or notifications to a variety of endpoints such as email, SMS, or other applications in a lightweight, scalable manner. It is designed to enable communication between distributed systems, allowing applications to communicate asynchronously through notifications in response to events.

Event-driven architectures leverage this capability to trigger actions automatically based on events happening within the system, making SNS ideal for alerting, signaling state changes, or broadcasting messages to multiple subscribers. This feature is particularly useful for microservices architectures where different components of an application need to react to events in real-time without direct coupling.

In contrast, the other options such as data storage, database management, and file sharing do not align with the primary function of SNS. Data storage typically involves a service like Amazon S3 or DynamoDB, database management relates to services that help with structured data, and file sharing deals with the transmission of files rather than the messaging and notification capabilities provided by SNS.