Terraform modules are a key part of writing maintainable and shareable Terraform configurations, recommended by HashiCorp for almost any configuration. Modules allow organizations to ensure consistent use of security features and best practices, and can be used to organize, encapsulate, and re-use configuration. The Terraform Registry hosts hundreds of modules contributed by the community, which can be used to enhance Terraform configurations. As complex configurations become more intricate, modules can simplify them, and they can also be shared within organizations or with the community.