I mean it doesn't have a disc drive and the base OS is Linux, so if the game you want to play doesn't work on Linux it won't work on the Linux version of Steam Deck, if that is what you're asking. If you know how to make isos and move them over if the game requires, you can install windows on the steam deck and basically run anything that the steam deck can handle hardware wise whether its on steam or not. Ive seen people who installed windows on it or also kept the original Linux Steam OS play many non-steam games. Some of these other devices were built with Windows though from the ground up though if you don't want to reinstall anything or deal with drivers, I personally plan on getting a Steam Deck here in a few months next Christmas then replacing Linux with Windows so i know for sure my software will work as sacrilegious as it is.
Lol, wooosh. A disc drive is an optical drive like a Blu-ray, DVD, or cd drive. Go ahead,show me the built in disc drive on a steam deck and not a USB connected one.
Yes HDD are disc based tech, yet I've never heard them refered to as just a disc drive without the hard despite having a platter disc in them. While not being the end all be all, wikipedia has disk or disc drives listed as referring to purely optical media.
And I use them to access a plethora of media from old back ups/family pictures, DVDs/Blu-ray, backing up said DVD/Blu-ray to Plex if I like them that much I want them digitally, old games(my oldest still useable disc is my 1998 minted "GOTY" Diablo 1.) Also just never hurts to have the ability to burn a CD or DVD either, though mainly still get the use out of CD burning for cars without an aux.
Oh, I obviously interpreted that as meaning a hard disk drive (which SSDs are still commonly referred to as HDDs) since we were discussing modern PCs. Many years ago external physical file transfer mostly transitied away from using actual spinning disks to USB storage, and even that has been mostly supplanted by network connected storage for several years.
Man, I hear "disc drive" & I think "hard disc drive". I've connected optical drives when USB boot wasn't supported, but the last time I voluntarily used a disc drive was to test an M-Data disc burned to silicon. But yeah, none of these new devices have a HDD or optical (or floppy disk, for that matter).