What is an AWS Lambda trigger?

An AWS Lambda trigger refers to an event that initiates the execution of an AWS Lambda function. In the context of serverless computing, triggers are crucial because they act as the mechanism that links events—such as changes in an S3 bucket, updates to a DynamoDB table, or HTTP requests through API Gateway—to the execution of a code snippet within the Lambda function. This allows developers to build applications that respond automatically to specific events without needing to manage servers or infrastructure, making them highly scalable and flexible.

Triggers enable applications to process data in real-time or to respond to user actions, thus facilitating a more dynamic interaction model. For example, if a new file is uploaded to an S3 bucket, a Lambda trigger can execute a function to process that file immediately upon its arrival, streamlining workflows and reducing latency. This capability is a fundamental aspect of the event-driven architecture that AWS Lambda promotes.

In contrast, other options describe different functionalities within AWS. Scheduled tasks running in AWS refer to services like AWS CloudWatch Events or EventBridge, which can be used to invoke Lambda functions at specified times rather than in response to real-time events. A service monitoring application performance could refer to AWS CloudWatch itself, which collects and tracks metrics but does not execute functions