Slight correction. Last generation was the Xbox One (already a confusing name because some people thought that was referring to the original first Xbox)

A few years into the generation they updated the Xbox One, putting it into a smaller form factor called the Xbox One S, and at the same time released a spec bump model called the Xbox One X. I don't believe any of these are still available for purchase.

The new generation has the smaller/lower-powered Xbox Series S, and the higher-specced Xbox Series X. Leaving the overall generation with seemingly no name, other than "Xbox Series" I guess?

But yes, the names are terrible because S and X both refer to consoles from last gen and current gen.