Beginner's doubt - IFC concept

[MuriloNoleto]

Hi everbody.
I'm begginer in the IFC topics and I read the concept of IFC format, but i dont understand what's the difference enter IFC 2x2 and 2x3. It's just the version/uptade of format (like AC 12, 13, 14, ...) or each format presents especific and differ properties?

Thanks.