WTF is Lambda?
Lambda is an abstract compute service where all you need to do is upload your code… AWS manages the servers for you. Lambda works in an event driven, orchestration manner and as a result of a request via API gateway or an ALB.
Serverless Application Model (SAM)
SAM is a CloudFormation extention optimized for serverless application. It’s basically macro library that enables serverless applications to use a more consise syntax for common patterns like functions, APIs, and tables.