A taser also fires small barbed metal probes. One goes out straight level, the other goes out a 4 degree downward angle to create probe separation. He wider the separation the more likely you are to achieve NMI (neuro muscular incapactitation)
Cops are trained to aim for the body preferably the back.
Those metal darts CAN seriously injure or even kll depending on where they strike the body. Penetration of eyes, skull and trsicles have occurred.
It's less lethal, but not a 100% guarantee. Without training it can be fairly dangerous.