What CloudFormation is & the model

Templates, stacks, managed provisioning.

CloudFormation is AWS’s built-in infrastructure-as-code service. You write a template — a declarative document listing the AWS resources you want — and CloudFormation creates and manages them as a single unit called a stack. Because it is a native AWS service, there is nothing to install and no separate state file to babysit: AWS itself stores the stack state, tracks every resource, and knows how to create, update, and delete each one through its own APIs.

That native integration is the whole pitch versus a third-party tool. CloudFormation understands AWS resource lifecycles first-hand, handles rollback automatically when something fails, manages dependencies between resources, and is supported by AWS as the substrate under higher-level tools (SAM for serverless, the CDK, which synthesizes CloudFormation). The trade-off is that it is AWS-only — this is the AWS-native path, not a multi-cloud one.

Templates, stacks, resources

Three terms anchor everything. A template is the declarative source document. A resource is one AWS thing in it (an S3 bucket, an EC2 instance, an IAM role). A stack is the deployed instance of a template — the collection of resources managed together, created from one template, and deleted together. Update the template and update the stack; delete the stack and CloudFormation removes the resources it created, in dependency order.