Call it whatever. If most guys are in a group, its a group ride. If most guys are racing, attacking, blocking, bridging, contesting the sprint, it's also a race. It can easily be both. Sanctioned races are group rides as well. If a bunch of kids hop on their bikes and say "first one to wherever wins", it's a race.
I'd say if guys are just pushing the pace for fun but not seriously trying to break away or win the sprint, it's not a race.