“Workers have a lease lifetime of 14 hours, when a worker approaches this maximum, no further invocations are forwarded to the worker and the worker is terminated.”
Serverless is a server. Your function sits as a zip file in S3 until someone calls it. Then it boots in a Firecracker micro VM on a bare metal box in an AWS account you can’t see. Every worker gets 14 hours before it is killed. The marketing calls this having no servers to manage.