Application Integration

Correct Answer: Ability to coordinate multiple AWS services into serverless workflows

AWS Step Functions is a serverless orchestration service that allows you to coordinate multiple AWS services into serverless workflows. It provides a way to define and manage the flow of tasks in a workflow, enabling you to build complex, multi-step applications using AWS Lambda functions and other AWS services. The ability to coordinate multiple AWS services into serverless workflows is a key benefit of using AWS Step Functions. While automatic scaling of compute resources and support for complex business logic are important features, they are not the primary focus or key benefit of Step Functions. The graphical user interface for designing and testing workflows is a useful tool but not the main advantage of using Step Functions.

Correct Answer: Tasks, states, and transitions that define a workflow

An AWS Step Functions state machine is composed of tasks, states, and transitions that define the workflow of a serverless application. Tasks represent individual units of work, states determine the flow and logic of the workflow, and transitions specify how the state machine moves from one state to another based on the outcome of each task. Lambda functions, API Gateway, and DynamoDB are AWS services that can be used within a Step Functions workflow, but they do not define the components of the state machine itself. EC2 instances, Auto Scaling groups, and Elastic Load Balancers are used for running and scaling applications, while S3 buckets, CloudFront distributions, and Route 53 are used for content delivery and DNS management, none of which are directly related to the components of a Step Functions state machine.

Correct Answer: Sending notifications to multiple subscribers via various communication channels

The correct answer is 'Sending notifications to multiple subscribers via various communication channels'. Amazon Simple Notification Service (SNS) is designed for sending notifications to multiple subscribers through different channels such as email, SMS, mobile push notifications, and HTTP/HTTPS endpoints. It allows for pub/sub messaging, where publishers send messages to topics, and subscribers receive those messages. The other options are not valid use cases for SNS. Storing and retrieving messages in a queue is a use case for Amazon Simple Queue Service (SQS). Providing a managed document database service is a use case for Amazon DocumentDB. Enabling secure communication between microservices is more related to services like Amazon API Gateway and AWS App Mesh, not SNS.