That's not at all how it works.

Terraform supports each of those providers, but the resources are specific to each provider.

You cannot use the same Terraform configuration on AWS and Azure.

Nor would you want to, per se. As far as I know, this is by design.

You can’t share provider-specific resources across providers of course, but you can absolutely share other configuration data across providers. I find it extremely useful - for example it’s fairly trivial to bounce between scaleway, AWS, DO, Vultr, etc.

You can also use the same basic cicd pipeline to manage infrastructure on different providers instead of a custom pipeline for each provider tailored to their tool.