I’ll try: Terraform replaces all the actions you’d do in the AWS (or other cloud provider) console or API with declarative configuration code. This means you can parametrize it, version control it, compose it, etc. and generally treat it like code.

It would be overkill for many things that have a single, fairly static configuration, but for things like ensuring that a dev and prod cluster have the same configuration, it’s a lifesaver.