Terragrunt is an open-source tool that sits on top of Terraform to reduce repetition, enforce standards, and improve the management of complex infrastructure codebases. It enables teams to keep Terraform modules DRY by using shared configuration, remote state conventions, dependency management between modules, and environment-specific settings. Terragrunt is commonly used in multi-account, multi-region, or multi-environment setups to orchestrate Terraform runs consistently while keeping modules clean and reusable. It is aimed at experienced Terraform users who need structure, safety, and scalability without replacing Terraform itself.