World
A world is a claimable OWOT URL, like for example /exampleworldforwiki.
To claim a world you need to make an account (not a guest account).
World Settings
World owners can change world settings like ratelimits, themes, colors, background colors, world members, etc.
However, admins get extra world settings, like changing the background of the world.
Advanced world settings
If you click Advanced under Miscellaneous, you'll be able to change advanced settings such as cell dimensions, write intervals, rate limits, meta descriptions, private notes, NSFW status (barely used), logging edits, disabling global chat, limiting copying and a membership key.
World claiming and shown worlds
If you have an account and go to your profile you can see a list of your claimed worlds and an input box which allows you to claim a world.
WOTD
Worlds can be requested at /fp/submit to get added to the poll so they can become a WOTD.