Terraform

Terraform is a tool for creating and changing cloud infrastructure, servers, databases, networks, permissions, by writing it down in configuration files instead of clicking through a web console. It keeps a state file recording what it built last time. When you run it, it compares your config with that state and the real cloud, then shows a plan: what it will create, change or destroy. Only after you approve does it make the API calls. This makes infrastructure reviewable and repeatable like code, though the state file is now precious: if it drifts from reality, or two people apply at once, plans can go wrong.