Weird question: you use Terraform to manage the cluster nodes themselves, and then you use k8s YAML (or Helm charts or something else) to manage the k8s resources, right? You don't manage the k8s resources from Terraform, do you?
Correct. I like to think of it as “infrastructure” (things managed by Terraform that define the structure) vs “deployments” (actual apps deployed on that infrastructure). The line gets blurry because you can actually deploy many types of apps with Terraform too if you want, but typically you would use Helm or similar solution for that.