Game Pass is the subscription to Xbox’s huge game catalog. But it’s only limited to one device, and there are no benefits of Xbox Live Gold included. With Game Pass, you just get to enjoy the Xbox game catalog on either your console or PC.
On the other hand, Game Pass Ultimate is an all-in-one subscription that gives you access to the Xbox game catalog, Xbox Live Gold benefits, an EA membership subscription, and the freedom to play on PC, console, and android devices.