It's not terribly complicated either - if you are only concerned with code, then your deployment is 'serverless' in the sense that _you are not concerned with servers_.
Of course 'servers' are involved; the point is whether that's of concern to your deployment.
In an old job, in an effort to disambiguate, I would always use "computer" to mean hardware (losing battle).
I would say "machine" means the hardware and/or the operating system of the "server" (which is a fancy word for "computer").
The "and/or" part being very important!
This is the problem with most abstractions in IT I guess - they're beautiful and clean until reality bites.