The two steps that are required to provision new infrastructure in the Terraform workflow are init and apply.
The terraform init command initializes a working directory containingTerraform configuration files. It downloads and installs the provider plugins that are needed for the configuration, and prepares the backend for storing the state. The terraform apply command applies the changes required to reach the desired state of the configuration, as described by the resource definitions in the configuration files. It shows a plan of the proposed changes and asks for confirmation before making any changes to the infrastructure. References =
[The Core Terraform Workflow], [Initialize a Terraform working directory with init], [Apply Terraform Configuration with apply]

To output returned values from a child module in the Terraform CLI output, you need to declare the output in both the child module and the root module. The child module output will return the value to the root module, and the root module output will display the value in the CLI.
References = [Terraform Outputs]

This is not a responsibility of a Terraform provider, as it does not make sense grammatically or logically. A Terraform provider is responsible for exposing resources and data sources based on an API, managing actions to take based on resource differences, and understanding API interactions with some service.

Comprehensive and Detailed in-Depth Explanation:
* terraform validatechecks for syntax errors and internal consistencyin the configuration files.
* However, itdoes notcheck if resource configurations are valid with the provider.
Official Terraform Documentation Reference:terraform validate - HashiCorp Documentation

The module source path that does not specify a remote module is source = "module/consul". This specifies a local module, which is a module that is stored in a subdirectory of the current working directory. The other options are all examples of remote modules, which are modules that are stored outside of the current working directory and can be accessed by various protocols, such as Git, HTTP, or the Terraform Registry. Remote modules are useful for sharing and reusing code across different configurations and environments. Reference = [Module Sources], [Local Paths], [Terraform Registry], [Generic Git Repository], [GitHub]