This document introduces infrastructure as code (IaC) and the tool Terraform. It defines IaC as using code to describe, create, and manage infrastructure. The key benefits of IaC are the ability to rebuild infrastructure at any time, ensure consistency, and have a repeatable process. Terraform is then introduced as an open-source tool for building, changing, and versioning infrastructure safely and efficiently across various cloud providers and SaaS services. The document outlines Terraform's workflow of writing configuration files, planning changes, and applying changes to infrastructure.