The Site policy is the policy for the wiki and how you behave, edit etc.They must be followed or else it may result in a block, or three warnings, depending on the seriousness of what you have done.
To read the site policy click here.
The chat policy is the policy for when you go on chat. If you break a rule from this policy, you will recieve warnings and/or a block (depending on what you did).
To read the chat policy click here.