Which service provides real-time messaging for distributed applications in AWS?

The service that provides real-time messaging for distributed applications in AWS is Amazon Simple Notification Service (SNS). SNS is a fully managed messaging service designed for applications that require high-throughput and low-latency messaging. It enables the communication between decoupled components of distributed systems and allows you to send messages to multiple subscribers simultaneously.

SNS supports different message delivery methods, including push notifications to mobile devices, emails, and HTTP endpoints. This flexibility makes it ideal for real-time messaging, event-driven architectures, and broadcasting information to multiple subscribers.

In contrast, Amazon Simple Queue Service (SQS) is designed for message queuing, which means it provides asynchronous message delivery between components, allowing them to communicate without requiring them to be active at the same time. While SQS is great for decoupling services and managing message queues, it does not inherently support real-time messaging as SNS does.

AWS Lambda, on the other hand, is a serverless compute service that executes code in response to events. It does not provide messaging capabilities directly but can integrate with services like SNS or SQS to process messages. Similarly, AWS Step Functions is used for orchestrating distributed applications by defining workflows, not specifically for real-time messaging.

Overall, Amazon SNS stands out for