How many different types of zombie are there?
1) There's the type that just happen to be dead and arise as zombies for some inexplicable reason.
2) Then there's the type that get bitten by a zombie, and they themselves turn into one.
3) Then there's the Sideshow type one, that seems to be some kind of scientific experiment, or a virus gone wrong and out of control.
Are there more?
Each have differing attributes.
1) Can be grotesquely rotten, dependent on how long they have been dead.
2) Can be almost human and sometimes unable to be differentiated from the normal human, even if their brain is dead, and they stumble around muttering inconsequential vocal utterances, with only a bite mark, or bite sized missing flesh. Sometimes their reanimation can take time, whereby they have been gorged upon by, perhaps, several infected or affected zombies.
3) May have suffered some kind of wound, therefore the excessive blood spatterings, and the susceptibility to viral entry through the open wound/s.
They are classed, generally, as zombies, but they aren't all the same.