Question about a curved universe

[QUOTE=Enola Straight]
Ah, but if the universe as a whole is expanding, wouldn’t the space between and within individual atoms proportionally expand at the same rate?

Various points brought up here:

and here:

[/QUOTE]

Is it the space between that expands or the atoms themselves? I’m confused as to what is going on with space “growing” vs fabric of space “stretching” ( i.e. affected by gravity ).