When you initialize Terraform, where does it cache modules from the public Terraform Module Registry?

When Terraform is initialized, it caches modules from the public Terraform Module Registry on disk in the .terraform sub-directory within the working directory of the configuration being executed. This behavior allows Terraform to efficiently manage and reuse modules, avoiding the need to download them repeatedly for subsequent runs. The caching in the .terraform folder helps streamline operations, as Terraform can quickly access these modules without re-fetching them from the registry every time you run a command, resulting in improved performance during the execution of plans and applies.

The use of a specific sub-directory also keeps the module cache organized and contained, ensuring that it does not interfere with other files in the project and allowing for clean management of the Terraform environment. Moreover, it follows common practices in software development where dependencies and caches are often kept in dedicated directories within a project's root to facilitate version control and maintenance.