Huh...
So imagine you've got 5.1 speakers aka traditional surround. Centre, left, right, rear left, rear right. And a subwoofer which is the .1 part. Atmos in this context could be expressed as 5.4.1 for which the configuration would be centre, left, right, rear left, rear right (that's the 5), upper left forward, upper left rear, upper right forward, upper right rear (that's the 4), and a subwoofer which is again the .1.
Sound can be encoded to come out of any one of those speakers at any given moment, just like in 5.1 (or stereo, for that matter).
Atmos is effectively putting you in the middle of an enriched soundstage, that's all.
Make a bit more sense?