>a “server” just means a computer that serves content

From a software point of view, you are correct. You can use any machine you want for that use case.

It's one thing to say - "You can use this computer as a server / to serve content." It's something different to say "this is computer is a single board server" when it actually isn't.

I know I'm being pedantic but I work in Product for a server manufacturer. I'll stop now.