The document discusses serverless architecture and function as a service (FaaS). It notes that serverless allows developers to deploy code as independent functions that are triggered by events and only charge when functions run, scaling automatically. Functions have no disk access and are stateless, running in ephemeral containers. Serverless fits well for static websites, data stream analysis, file processing, and actions users directly pay for on demand. The document outlines Amazon's serverless ecosystem and provides an example architecture and use cases. It also discusses benefits like lower costs and easier scaling but notes potential drawbacks around vendor lock-in and cold starts.