What is the difference between voluntary and involuntary manslaughter?

While the People were not required to make an election between voluntary and involuntary manslaughter in charging appellant with manslaughter (People v. Wild (1976) 60 Cal.App.3d 829, 833, 131 Cal.Rptr. 713), they chose to do so here. Once the People make such an election, they are precluded from changing their minds midstream without moving to amend the information. Appellant here had no notice that the prosecution was proceeding on any theory of involuntary manslaughter until the time of the final argument. Appellant prepared his defense on the theory that the case was either "voluntary or nothing." Accordingly, I can only conclude that the information here also did not meet the accusatory pleading test.