"Et que font ces groupes ?"
The verb in the sentence is "font", a conjugation of "faire", meaning "to do" or "to make". If the question was asking what the groups "are", the verb used would be "etre" not "faire".
That would mean something different, you would then assume the groups to be an object, not a subject of the sentence. Generally in English it is pretty important to have the subject before the verb.