Outside of the required_providers block, Terraform configurations can refer to providers by either their local names or their source addresses. The local name is a short name that can be used throughout the configuration, while the source address is a global identifier for the provider in the format registry.terraform.io/namespace/type. For example, you can use either aws or registry.terraform.io/hashicorp/aws to refer to the AWS provider.

This is the command that always causes a state file to be updated with changes that might have been made outside of Terraform, as it will only refresh the state file with the current status of the real resources, without making any changes to them or creating a plan.

The terraform validate command is used to check that your Terraform configuration files are syntactically valid and internally consistent. It is a useful command for ensuring your Terraform code is error-free before applying any changes to your infrastructure.

This is how Terraform determines dependencies between resources, by using the references between them in the configuration files and other factors that affect the order of operations.

A provider configuration block is not required in every Terraform configuration. A provider configuration block can be omitted if its contents would otherwise be empty. Terraform assumes an empty default configuration for any provider that is not explicitly configured. However, some providers may require some configuration arguments (such as endpoint URLs or cloud regions) before they can be used. A provider's documentation should list which configuration arguments it expects. For providers distributed on the Terraform Registry, versioned documentation is available on each provider's page, via the "Documentation" link in the provider's header1. Reference = [Provider Configuration]1