Setting Triggers in Lambda Function

Lambda functions can run when something happens (an event occurs) to another AWS service like a file upload to S3 or a change to a DynamoDB table. Lambda functions can also run on a given schedule.

Triggers can be set, disabled or deleted from the Triggers tab in the console.
trigger
To add a trigger, click on the "Add Trigger" button, then select the service, and then for S3, select bucket name, event and optionally supply additional details prefix and suffix.
trigger
The details of the triggers can be viewed by clicking the Details link. Here is a sample of few triggers created.
trigger

When triggers are created, events are added to the relevant service. For example, events are added to S3 when the previous triggers are added as shown below.
trigger

The triggers can be disabled and deleted as well. Disable option can be used for temporary testing or when it is temporarily not required.