Function as a service (FaaS) is a category of cloud computing services that provides a platform allowing customers to develop, run, and manage application functionalities without the complexity of building and maintaining the infrastructure typically associated with developing and launching an app.[1] Building an application following this model is one way of achieving a "serverless" architecture, and is typically used when building microservices applications.
FaaS was initially offered by various start-ups circa 2010, such as PiCloud.[2]
AWS Lambda[3] was the first FaaS offering by a large public cloud vendor, followed by Google Cloud Functions, Microsoft Azure Functions, IBM/Apache's OpenWhisk (open source) in 2016 and Oracle Cloud Fn (open source) in 2017.