> not only create servers, but also databases, caches, load balancers, queues
These things are, I would say unquestionably "infrastructure".
> firewall settings, routing rules, Secure Sockets Layer (SSL) certificates
These things are more or less configuration, basically files that exist on the above.
And yet, as you say, it's common to manage them using provisioning tools like terraform.
> These things are more or less configuration, basically files that exist on the above.
Part of the different perspective feels like managed cloud vs on prem.
In the former, these are all actually things to be created, albeit as an abstraction on the underlying implementation. Which you don't have access to.
In the latter, they're configurations on things you have access to.
> not only create servers, but also databases, caches, load balancers, queues
These things are, I would say unquestionably "infrastructure".
> firewall settings, routing rules, Secure Sockets Layer (SSL) certificates
These things are more or less configuration, basically files that exist on the above.
And yet, as you say, it's common to manage them using provisioning tools like terraform.