In the Linux world everything is file, in the Serverless world everything is an HTTPS interface.
Serverless applications by their nature are heavily decomposed into a variety of services, such as autonomous functions, object storage, authentication services, document databases, and pub/sub message queues. The interfaces between these services are typically HTTPS. When you’re using the AWS SDK to call an AWS services, the interface it’s calling under the hood is an HTTPS interface. This is true for the majority of cloud platforms, with some alternative protocols occasionally being used (WebSockets and MQTT) in specific use cases.
In the same way that in Linux you can access all the resources of the underlying machine through the file system, in a serverless world you can access all the resources of the underlying cloud platform through an HTTPS interface.
Read more at Serverless.Zone