The first thing I did was throw drives into my PC set up samba and minidlna so my SO and I could stream video to the TV.

But in an online discussion, someone made the argument that it needs to be a dedicated machine with unattended updates with providing storage as its only purpose or something to that effect. That seems overly limiting to me, but that seemed like a pretty common sentiment.

Surely there's a line somewhere between someone making a share on their PC or attaching a USB drive to their router and a commercial NAS device. I don't know where that line is, so I tend to be pretty conservative and assume a NAS device is dedicated to the purpose, whether DIY or purchased, but if it runs a bunch of other services, now it's a "server" and not a NAS.

That's why I'm suggesting the language here be more precise.