Not an internal hard drive or integrated NIC but old games that Microsoft was kind enough to bestow the software license unto you. I have Playstation so I'm assuming it's similar to PS Plus but somewhat better because Microsoft are slightly less greedy scumfucks than Sony. I swear some of these soybitch consoomers are grown in tubes and were born yesterday.
Microsoft also still does their monthly games thing that PS Plus ripped off of, with "Games with Gold", where you get two Xbox One and two Xbox 360 games monthly. Except the 360 games are for keeps on your account, while the XBOne games only work while you have an active Gold account.
Game Pass uses a video streaming model, where there are something like 100 games on the service you can download and play while your sub's active, and they switch games out a lot. The big selling point is that anything Microsoft owns gets released on Game Pass the day of release, so you can decide whether you want to buy the game outright for $60, or spend $15/month and play it there. It's an aggressive business model that's currently in its halcyon days, but it's very concerning to anyone who isn't an NPC and can see further than a few minutes into the future. It both promotes not being able to own your games in any capacity, but also subsidizes garbage, so customers can't even vote with their wallets.
Remember how Netflix put up Cuties last year, a movie that straight up has legally-defined child pornography, and just... got away with it? Well, it was subsidized by every single person with a Netflix subscription, so, technically, everyone paid for it, because of just how that model works. It's terribly dystopian, but that's just what happens when wokies trick the public into subsidizing all of their shit.
But to Microsoft's credit, at least they're not as greedy as Sony when it comes to their back catalog. If you have an old-ass copy of Morrowind you bought at launch 19 years ago, you can put that same disc in a Series X, and it'll download the whole game, and work, and run better than ever. No paid account required. That's smart.
Sony, on the other hand, outright sells "PS2 Classics" on their storefront, but that doesn't mean your PS3/4/5 can run them from the disc. Did you buy PS2 games on your PS3, and now you want to play those on your PS4? Tough shit. Do you have a copy of Psychonauts on-disc for PS2, and you see that it's on the PS4 storefront? Tough shit. You wanna play it on your new thing? You gotta re-buy it.
And that just causes negative perception towards the PlayStation brand, and makes Xbox that much more appealing. It's a stupid petty thing to lose customers over, but at least Microsoft's the
smart evil megacorporation now.