Could someone please explain what they're doing that is different to the standard installation of Zsh and the key differences between the two? If possible could you explain which would be preferable for a user new to zsh?
As there has been one issue of links breaking, here are the quotes:
1: By John Stevenson
Prezto has been rewritten by the author who wanted to achieve a good zsh setup by ensuring all the scripts are making use of zsh syntax. It has a few more steps to install but should only take a few minutes extra.
2: By JonnieCache
In case it isn't clear, prezto is a fork of oh-my-zsh which has basically been rewritten bit by bit to make everything much cleaner and saner. I highly recommend it. The history-substring-search and syntax-highlighting modules are brilliant. You will be the envy of all your friends and neighbours.