@woolf1974 said in I dont know what terms to search for file structure:
A few follow up questions.
Is the list of emulators a complete list for RetroPie?
it should be, but remember retropie is available on multiple hardware platforms, eg all the different pi models, x86 PC, some other SBCs, etc. all of these platforms will support a different subset of the available emulators.
I have a few listed in my roms list that are not included. So is the list complete? Or is it only complete as far as the pre-installed emulators in RetroPie?
on the retropie images or manual installs, only a subset of the most commonly used and worthwhile emulators are installed by default. others will be supported, but again - it depends on the hardware platform. you can install additional available emulators via https://retropie.org.uk/docs/Updating-RetroPie/#updatinginstalling-individual-packages
Can additional emulators be added that are not currently included?
yes, if they support the hardware and you write the build/install script.