Voluntary manslaughter is considered homicide but not murder under the legal definition. I realize the confusion in my earlier post now, my wording wasn't wrong but I didn't explain it clearly enough. Homicide includes manslaughter and murder (murder being the more serious crime). Murder is divided into three degrees. First is the most serious kind of intentional killing. Second degree is murder during the commission of a felony, and also requires a life sentence like first degree. Third degree is less serious and then below these you have voluntary and involuntary manslaughter that are lesser offenses.

The degrees of felonies is a separate thing from the degrees of murder. The relevance of voluntary manslaughter being a first degree felony is that the max sentence is 20 years max and 10 year minimum. The three kinds of murder offenses aren't included in the felony grading, they have their own maximum sentences.