Cloud blurs the line, since a lot of cloud offerings are managed where you're really doing both at once when you define the managed offering.
Terraform is literally a program that looks at a declarative configuration file, looks at a state file, queries some APIs, and then submits some API calls. That is all it does.
There is no "infrastructure", or "config", or "cloud". It's literally just calling HTTPS APIs, the same way it would call a system call or a library function. Call function, pass input, receive output.
There is no magic sauce. There is no difference between it and any other tool that has a declarative configuration, a state, and operations to try to change things to match a desired state.
It's all configuration management. The words "infra", "orchestration", "cloud", etc is marketing bullshit. It's all just software.
But there is a very real difference between "Deploying a server" and "Modifying configuration files on that server". The former used to require actual physical actions in a data center and it's only in the world of modern virtualization and clouds that it has become possible to do it through an API. Where as the latter used to require secure access to an individual physical machine, often over SSH after someone had done the physical work of setting it up. Again, it's only in the world of modern virtualization and clouds that you can start to do that through APIs.
It is only modern clouds that has blurred the lines between these two by abstracting away the difference between the physical server and the software running on it behind APIs.
Conceptually, it can still useful to think of "infrastructure orchestration" and "configuration management" as different things and different categories. Like I said, in many cases cloud offerings significantly reduce the utility of those categorizations - because they often abstract both steps behind a unified API where you are launching virtual infrastructure (still largely using the same conceptions that were used when it was physical) and defining its configuration at the same time through the same interface.
None of this is marketing speak. It's just definitions and categorizations. Sometimes useful, sometimes not. And all of it is orthogonal to what terraform does do or should do. Whether or not terraform is "infrastructure orchestration", "configuration management" or both is neither here nor there for the definition of those terms and considerations of their utility.
