Terraform providers are not part of the Terraform core binary. Providers are distributed separately from Terraform itself and have their own release cadence and version numbers. Providers are plugins that Terraform uses to interact with various APIs, such as cloud providers, SaaS providers, and other services. You can find and install providers from the Terraform Registry, which hosts providers for most major infrastructure platforms. You can also load providers from a local mirror or cache, or develop your own custom providers. To use a provider in your Terraform configuration, you need to declare it in the provider requirements block and optionally configure its settings in the provider block. References = : Providers - Configuration Language | Terraform : Terraform Registry - Providers Overview | Terraform

None of the above methods prevent credentials from being stored in the state file. Terraform stores the provider configuration in the state file, which may include sensitive information such as credentials. This is a potential security risk and should be avoided if possible. To prevent credentials from being stored in the state file, you can use one of the following methods:
Use environment variables to pass credentials to the provider. This way, the credentials are not part of the provider configuration and are not stored in the state file. However, this method may not work for some providers that require credentials to be set in the provider block.
Use dynamic credentials to authenticate with your cloud provider. This way, Terraform Cloud or Enterprise will request temporary credentials from your cloud provider for each run and use them to provision your resources. The credentials are not stored in the state file and are revoked after the run is completed. This method is supported for AWS, Google Cloud Platform, Azure, and Vault. References = : [Sensitive Values in State] : Authenticate providers with dynamic credentials

This is a secure way to protect sensitive data in the state file, as it will be encrypted at rest and in transit2. The other options are not recommended, as they could lead to data loss, errors, or security breaches.

Confidentiality: UsingHCP Terraform/Terraform Cloud's private registrykeeps the module configurations within your organization, ensuring privacy and access control.
Version Constraints: The private registry supportssemantic versioning, allowing you to manage versions of your modules as Terraform does natively.
Browsable Directory: The private registry offers a user interface to browse modules, making it easy for users within the organization to locate and manage modules.
This setup aligns with HashiCorp's design forprivate registry supportin Terraform, meeting all listed requirements for secure, version-controlled, and searchable module storage.