What is the primary function of the terraform init command?

The primary function of the terraform init command is to set up the working directory for Terraform. This command prepares the directory where your Terraform configuration files are located by initializing various components necessary for Terraform to function properly.

When you run terraform init, it performs several crucial tasks, including:

1. Module Initialization: It downloads the modules referenced in your configuration files, ensuring that all necessary code is available.
2. Provider Installation: It fetches the required provider plugins based on your configuration so that Terraform can interact with the specified cloud services or infrastructure.
3. Backend Configuration: It initializes the backend configuration, which determines where Terraform's state file will be stored, allowing for remote state management and collaboration.

This command is essential for getting started with Terraform as it lays the groundwork for executing further commands such as plan and apply, which actually make changes to infrastructure.

In contrast, options that involve applying changes, creating new resources, or destroying existing ones pertain to functionalities executed by the terraform apply or terraform destroy commands, which require that the directory has already been initialized successfully with terraform init. Thus, setting up the working directory is foundational before any infrastructure can be managed.