Which service allows you to run serverless applications without provisioning servers?

AWS Lambda is the service that enables you to run serverless applications without the need to provision and manage servers. It is designed to execute code in response to specific events, such as changes to data in Amazon S3 buckets, updates to a DynamoDB table, or HTTP requests via API Gateway. This model abstracts away the underlying infrastructure, allowing developers to focus solely on writing and deploying their application code.

Lambda automatically scales the execution of your code in response to incoming requests, meaning that you only pay for the compute time that you consume, without any idle server costs. This makes it ideal for applications with variable workloads, where you might need to process many requests occasionally but none at other times. Additionally, there’s no requirement to provision servers explicitly, which simplifies deployment and operational overhead.

The other options do involve the provisioning of some infrastructure or do not operate on a serverless model. For instance, AWS Elastic Beanstalk requires you to manage the environment and underlying resources, AWS Batch orchestrates the execution of batch processing jobs using EC2 instances, and AWS CloudFormation is a service for defining and managing cloud resources through templates but does not handle the execution of applications.