@nprofile1q... @nprofile1q... My definition:
I use "stock ROM" to refer to the system that comes pre-installed from the manufacturer, and "custom ROM" as an alternative to the stock ROM.
A custom ROM can therefore replace the stock ROM.
Yes, the definitions are generally vague.
Instead of "ROM," one could of course also say "OS." However, I only use "OS" for x64 and x86 hardware