Which file extension is commonly used for Terraform configuration files?

The commonly used file extension for Terraform configuration files is .tf. This extension indicates that the file contains the declarative configuration code which defines the desired infrastructure state and resources that Terraform will manage.

Terraform uses this format for its primary configuration files, which are written in HashiCorp Configuration Language (HCL), enabling the user to describe the infrastructure components in a human-readable format. The .tf extension is essential for Terraform to recognize and interpret the configurations when commands are executed.

Other file extensions serve different purposes within the Terraform ecosystem. For instance, .tfjson is used for JSON-formatted versions of the configuration files, which are less commonly manipulated directly by users. The .tfstate extension is related to the Terraform state files, which track the current state of the infrastructure and are critical for resource management by Terraform. The .terraf extension is not a recognized or standard file type within Terraform practices.