Difference between 1st degree and 2nd degree murder?

Premeditation is the difference. If a person gets involved in a fight that is an immediate reaction. But if the person hesitates long enough to pull a knife, pick up a stick or other weapon that is considered premeditation and is murder one. If person comes home and finds their partner in bed with someone and attacks with only their fists and a person dies that is not premeditation, and is murder two or manslaughter. But if the person hesitates long enough to pull out a knife, or reach over to a night stand and pick up a gun that is premeditation. Being married or unmarried has nothing to do with it.