The terraform apply command changes both the cloud infrastructure and the state file after you approve the execution plan. The command creates, updates, or destroys the infrastructure resources to match the configuration. It also updates the state file to reflect the new state of the infrastructure. The .
terraform directory, the execution plan, and the Terraform code are not changed by the terraform apply command. References = Command: apply and Purpose of Terraform State

Some backends support state locking, which prevents other users from modifying the state file while a Terraform operation is in progress. This prevents conflicts and data loss. Not all backends support this feature, and you can check the documentation for each backend type to see if it does.

This command will upgrade the plugins to the latest acceptable version within the version constraints specified in the configuration. The other commands do not have an -upgrade option.

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.

Before using a remote backend in Terraform, it is mandatory to runterraform init. This command initializes a Terraform working directory, which includes configuring the backend. If aremote backend is specified, terraform initwill set up the working directory to use it, including copying any existing state to the remote backend if necessary.References= This principle is a fundamental part of working with Terraform and its backends, as outlined in general Terraform documentation and best practices. The specific HashiCorp Terraform Associate (003) study materials in the provided files did not include direct references to this information.