Infrastructure as Code (IaC) is the practice of managing and provisioning infrastructure through machine-readable definition files rather than physical hardware configuration or interactive configuration tools. IaC enables teams to version, test, and deploy infrastructure with the same rigor applied to application code, transforming infrastructure management from a manual, error-prone process into an automated, repeatable one. A key distinction in IaC is between declarative approaches (defining desired end state) and imperative approaches (defining step-by-step procedures)—understanding when to use each fundamentally shapes how infrastructure is designed, validated, and evolved over time.