here). This is just my simple version.
Three major types of zombies:
1. First, you have your zombies that are controlled by Voodoo or some kind of Necromancy. Justine Larbalestier refers to them as "Voudin-inspired zombies" in Zombies vs Unicorns. These are the kind of zombies that you see in White Zombie (1932) and the Anita Blake books.
I walked with a Zombie (1943):
Magic controlled zombies vary. You never know how smart or fast they are going to be so it's best to just avoid them altogether. You never know when demonic possession might just bite you in the ass.
2. Then you have your classic George A Romero zombies. These zombies are the personification of death. Slow and unfeeling, these zombies will stop at nothing to eat your brains. Romero is often mentioned whenever someone talks about zombies because he essentially set up the rules for the modern zombie. Romero's zombies are slow, have little brain activity, run on instinct to feed, and their victims die and are reanimated as zombies.
Night of the Living Dead (1990):
This zombie comes in a myriad of different forms. Some, like Romero's, have little to no explanation of where the zombies originated from. Others, like the book Feed, have a scientific explanation for where zombies originated from. Even though some zombies may have human speed, they are NOT fast. Put it down to none functioning adrenal glands if you want, but either way speed is your best weapon against this mass of undead.
3. The third form of zombie is probably the most controversial - the fast zombie. These are the zombies of 28 Days Later and the book Hater. These zombies are often the result of human stupidity, but not always.
28 Days Later trailer (2002):
Zombies of this ilk are often fast and viscous. Instead of being ruled by the simple need to feed, these zombies are usually more rage inspired. As with all zombies, destroying the brain will usually put these souped up zombies to final rest, but your best bet is to get very far away. Some people (zombie-purists?) do not buy into the fast zombie idea. I'm usually one of these people myself, but in the end a good film is a good film.
I found this video that sums up the evolution of the zombie rather nicely (after I typed this all up of course):
So there you have it. The three major types of zombies.