Terraform Registry Lambda Module: role_name vs lambda_role?

When using the AWS Lambda module from the Terraform Registry, what is the difference between lambda_role and role_name?

Do they both refer to the lambda's execution role? Based on the documentation (included below), it seems like the only difference is that one is a name and one is an ARN. Is that the only difference?

From the current docs:

• role_name:

  • Name of IAM role to use for Lambda Function.

• lambda_role:

  • IAM role ARN attached to the Lambda Function. This governs both who / what can invoke your Lambda Function, as well as what resources our Lambda Function has access to. See Lambda Permission Model for more details.