word choice - What's the difference between 'group' and 'grouping'?

I'm not a native English speaker and I was wondering the difference between those two terms.

From what I understood so far 'group' is a generic word used to denote a number of persons/things considered related in some way.
'grouping' is used to denote a group of people sharing a common intent or interest.

Is this the case? It seems that 'grouping' has a more specific meaning and that 'group' can be used always in place of 'grouping' (because it's a more general term).

So in which case do you use 'group' and in which one do you use 'grouping' instead?

Answer

When you use the word group your emphasis should be on the collection of things in the group.

How many people do you have in your group?

When you use the word grouping your emphasis should be on the act of forming the group rather than the group itself.

Which grouping would be better- girls in one group and guys in another, or else adults vs children?