Which service allows the execution of serverless functions driven by events?

Amazon Lambda is designed specifically to enable the execution of serverless functions in response to various events. It allows developers to run code without having to provision and manage servers, which streamlines the development process and reduces overhead costs. When an event occurs—such as an update to an Amazon S3 bucket, a message in an Amazon SQS queue, or an HTTP request via Amazon API Gateway—Lambda functions can be automatically triggered to perform specific tasks.

This event-driven architecture allows for responsive applications that scale automatically based on demand, as Lambda handles the scaling of compute resources in the background. The billing is also based on the actual execution time of the code, making it a cost-effective option for applications that require periodic or unusual bursts of computation.

The other options, while useful services within the AWS ecosystem, do not specifically offer serverless function execution driven by events. AWS Elastic Beanstalk is a platform as a service (PaaS) for deploying applications but requires managing the underlying infrastructure. AWS Fargate allows for serverless container management but focuses on running containers rather than executing standalone functions. Lastly, Amazon Lightsail is aimed at simplifying cloud hosting but does not include the specific event-driven, serverless execution model that Lambda provides.