## TL;DR

Terraform by HashiCorp is the dominant Infrastructure as Code tool, using HCL (HashiCorp Configuration Language) to declaratively define and provision cloud resources across 3000+ providers. State file tracks real-world resources; plan shows pending changes.

## Core Explanation

`terraform init` (download providers), `plan` (preview changes), `apply` (provision), `destroy` (teardown). Remote state (S3 + DynamoDB) for team collaboration and state locking. Modules enable reusable configuration. Workspaces isolate environments. Terraform Cloud/Enterprise adds VCS integration, policy as code (Sentinel), and cost estimation.

## Further Reading

- [Terraform Documentation](https://developer.hashicorp.com/terraform/docs)