What does terraform refresh really do?

Question

While using terraform to deploy a fairly large infrastructure in AWS, our remote tfstate got corrupted and was deleted.

From the documentation, I gather

Answer 1

I know this is a little late to the party but in my recent dealings with terraform I read it still keeps a local state file tfstate.backup in case the remote state file is corrupted. Apparently, I haven't tried this, you can then do terraform state push and it will push the backup to the remote.

Cheers