Difference between non-mahram friendship and non-mahram love relationship?

I just want to know the difference between these two. Someone was actually arguing with me about non-mahram friendship and non-mahram love relationship and I told him that for me non-mahram love relationship and non-mahram friendship is equally haram no matter you love or just friends. Am I right or wrong? Please give me reference from Quran or some proper reference from hadeeth. Because people so many times said we are just friends and this is not as much haram as boyfriend and girlfriend relationship. And they thought little haram is ok. Please tell me the punishment or sin is equal or not?