Can you transport Xbox 360 / One games on a Harddrive of some sort on a Series X?

If you have an Xbox One with an external USB 3.0 hard drive connected to it with games installed on it. Then just disconnect the drive from the Xbox One, and connect it to the Series X, the drive should be recognized, and you should be able to play the games without having to install them.

If they were to put it a bigger ssd internally the price of the series x would rocket so to keep prices at a reasonable level these 1tb ssd drives sold separately and you only need them to play series x games once the internal ssd is full however you can
still use standard external harddrives to play xbox one 360 and og games from and yoi can also store series x games on them you just cant play the series x games from them so it might mean a little more transfering around of series x games (which will move
much faster than hames move now) so for a fair while you probably wont even need the plug in ssd drive.

To use Xbox 360 games with the series S you must use digital copies. There is no sort of disc to digital program currently announced, and no one here will know about it before some kind of press conference or news release

A Series X has a disc drive.

Why not get the Series for yourself and give the X1X to the kids?

Yes, if you purchase the game from the Xbox 360 marketplace, you can play it on the Xbox 360, Xbox One or Xbox Series X|S.

As for what Hardcore Games said, you can still buy Xbox games for the Xbox 360, and play them on the Xbox 360, and if they are backward compatible, play them on the Xbox One & Xbox Series X|S.

All Xbox One games can be played on the Series S/X via backwards compatibility. Kind of like how you can play 360 games on the One now. You would be playing the One version of the games.

With Cross Gen Editions/Smart Delivery, you're buying the One version and get an upgrade to the Series S/X version of the game when you get the new console instead of having to buy the Series S/X version and you an take advantage of some of the upgraded
features.