What is a trigger?
Trigger is an event that causes the AWS lambda function to execute. Let’s understand this with an example of API gateway triggers. when an HTTP request comes to the system through the API gateway, then API gateway will trigger the AWS lambda function.
Programming model for AWS Lambda
The lambda programming model has three parts —
Trigger
Handler function
Code
https://medium.com/swlh/execute-a-basic-aws-lambda-function-without-any-triggers-a10af53b03e2