Difference between flutters and kicks?

Claire • 2 MCs in 2014, hoping for a sticky bean third time around, due Nov 2015 🙏
Hi ladies, am just curious if I'll know the difference between movement/flutters from little bub and kicks? Is it a strong feeling? I can feel little one being more active but can't say whether it's anything more than 'stronger movements'! I'm currently 21 weeks x