AWS Lambda is Amazon Web Services’s Functions-as-a-Service (FaaS) offering. It allows developers to run their code in the cloud, without having to worry about provisioning or managing specific servers. Instead, devs can upload a function to Lambda and have it run only when it’s triggered.
As with most serverless products, one of the big advantages of AWS Lambda is that it scales automatically, so developers don’t have to worry about provisioning more machines if their application goes viral – Lambda handles that automatically.
It also charges developers only for the compute their functions actually use, so they don’t have to worry about racking up big server bills for keeping their functions in the cloud even when their application isn’t seeing much use.
The other major cloud providers offer similar FaaS services; for example, GCP offers Cloud Functions and Microsoft has Azure Functions.