What is Function as a Service (FaaS)?

Function as a Service (FaaS) is a serverless type of cloud computing service that allows users to develop, run, and manage functionality of an application without having to provision and manage the underlying compute resources. Without having to manage servers and by only paying for what you need, you have the time and the resources to focus on your business and the application itself, rather than the infrastructure supporting it.

With FaaS you can do programming or upload modular pieces of functionality (or code) into the cloud that can be independently executed and without the hassle of having to manage your own server. This means developers can make changes to applications on the fly. Prior to FaaS, you would have to provision servers to handle an entire load but now scaling and provisioning are done automatically for you through the different functions (or pieces of code) that you deploy.

FaaS use cases mostly include on-demand services that can be shut down when not in use, saving you the cost of running a server continuously.  Code is triggered by a user event (like someone clicking on a web page) which then calls other servers to execute the command.