Both Frankenstein’s, and Zombies are derived from dead people. Zombies are dead humans brought back to life by magical means to become mindless living dead creatures whose flesh is slowly rotting. Within a short number of years they will totally decay into nothingness despite being technically immortal in nature. Before that time they will attack any living thing, including humans, to feed their single minded cannibalistic lust for flesh and blood. Their deadly lust can be interrupted by magical means and then they become the slave of the magic master. This servitude is something they have in common with Frankensteins.
Zombies can create other zombies by passing along the supernatural zombie virus to living humans through their blood, saliva, and even the air. Some mad scientists and the government have also duplicated the virus to create zombies from living humans as well. Reanimation of corpses however requires the real supernatural virus or a magical catalyst.
Frankenstein’s are monsters composed of many body parts from various dead humans that are stitched together by mad scientists, necromancers, wizards, and sorcerers who may employ magic, alchemy, and science to animate their newly created patchwork corpse. Sometimes mechanical parts are apart of the mad mix thereby giving us a FrakenCyborg. The final animated spark can be bursts of metaphysical energy , lightning strikes, or some other high power discharge. Once animated they are alive rather than living dead in nature. Their flesh does not rot. Their minds have intelligence to varying degrees and they can be quite human in nature despite their hideous appearance. They can be gentle or ferocious in behavior depending on their creators influence since the Frankensteins mind is quite child like. They can also be made to serve a master via hypnosis, or magic although their free will can fight this unlike zombies. If created by a necromancer they can still be under their control despite not being dead. The creation is made of dead parts after all. The Necromancer channels the souls belonging to the various body parts to influencing the entire Frankenstein.