1. provider.tf = Terraform Configuration – It keeps track of the infrastructure detail

2. .tfvars = The tfvars file extension is in the root folder of an environment to define values to variables ,*.tfvar file to load in defaults as they are automatically loaded .you can have your orchestration Automator dynamically create a tfvars file to define defaults such as Region, environment (dev, test, stage or prod) cidr_blocks, subnet ranges, etc.

3. terraform.tfstate = This state is used by Terraform to map real world resources to your configuration, keep track of metadata, and to improve performance for large infrastructures , The primary purpose of Terraform state is to store bindings between objects in a remote system and resource instances declared in your configuration. When Terraform creates a remote object in response to a change of configuration, it will record the identity of that remote object against a particular resource instance, and then potentially update or delete that object in response to future configuration changes.

4. terraform.tfstate.backup = By default, a backup of your state file is written to terraform. tfstate. backup in case the state file is lost or corrupted to simplify recovery

5. terraform.lock.hcl = The dependency lock file is a file that belongs to the configuration as a whole ,Terraform automatically creates or updates the dependency lock file each time you run terraform init