What is terraform refresh intended to detect?

Terraform refresh is designed to detect state file drift, which refers to the difference between the actual infrastructure state and what is recorded in the Terraform state file. When changes are made to resources outside of Terraform—whether through manual updates, scripts, or other tools—those changes may not be reflected in the Terraform state. Running terraform refresh reconciles the current infrastructure with the state file by querying the existing resources and updating the state file accordingly. This allows Terraform to accurately understand the state of the infrastructure before applying any further changes, ensuring consistency and preventing potential issues that could arise from mismatches between the actual resources and the state file representation.

Other options like resource attribute updates, syntax errors in configuration files, and provider plugin updates, while relevant aspects of Terraform's functionality, do not pertain specifically to the primary purpose of the terraform refresh command.