Core, previously known as Xbox Live, allows for online multiplayer on Xbox and comes with access to 25 games for free including Doom Eternal, Forza Horizon 5 and Fallout 76.
There are currently four tiers to Xbox Game Pass: Core, Console, PC and Ultimate. Microsoft is also looking to complete its deal to acquire Activision Blizzard, which would add even more titles to Game Pass. This includes games from ZeniMax Media, which includes such popular series as The Elder Scrolls, Fallout, Doom, Wolfenstein, Dishonored and the recently released, Starfield.
Microsoft also sweetened the deal by offering every game it published to be available on the service on day one of its release. Over the years, it grew to encompass more than 100 games. It started in June 2017 with a limited catalog, which was a mix of titles published by Microsoft (aka first-party) and other publishers (third-party).
Game Pass is Xbox's 'all you can eat' gaming subscription, where one monthly fee gets you full access to dozens of games.
