why is it required to persist terraform state file remotely?

Question

I am new to terraform. Can someone please explain

why do we need to save .tfstate file in local or remote storage,

when terraform apply always refreshes the state file with new infrastructure.

Thanks in advance.

Answer 1

The state file tracks the resources that Terraform is managing, whether it created them or imported them. Terraform's refresh only detects drift in managed resources and won't detect if you have created new resources outside of the state file.

If you lose the state you will end up with orphaned resources that are not being managed by Terraform. If, for some reason, you are okay with that or you have some other way of sharing state with other team members/CI and backing it up then you're fine.

Of course, using Terraform's remote state neatly solves those things so you should use it if you care about any of those things or think you might need to in the future (you probably will).