在《Serverless Architectures》中对 Serverless 是这样子定义的：
Serverless was first used to describe applications that significantly or fully incorporate third-party, cloud-hosted applications and services, to manage server-side logic and state. These are typically “rich client” applications—think single-page web apps, or mobile apps—that use the vast ecosystem of cloud-accessible databases (e.g., Parse, Firebase), authentication services(e.g., Auth0, AWS Cognito), and so on. These types of services have been previously described as “(Mobile) Backend as a service”, and I use “BaaS” as shorthand in the rest of this article. Serverless can also mean applications where server-side logic is still written by the application developer, but, unlike traditional architectures, it’s run in stateless compute containers that are event-triggered, ephemeral (may only last for one invocation), and fully managed by a third party. One way to think of this is “Functions as a Service” or “FaaS”.(Note: The original source for this name—a tweet by @marak—isno longer publicly available.) AWS Lambda is one of the most popular implementations of a Functions-as-a-Service platform at present, but there are many others, too.
它的中文直译就是「无服务器」，目前对于 Serverless 有几种解读方法：
在某些场景可以解读为一种软件系统架构方法，通常称为 Serverless 架构
而在另一些情况下，又可以代表一种产品形态，称为 Serverless 产品
可以理解为 Severless = FaaS BaaS