I searched google for this and I found that this is some sort of license but still didn't quite understand it after reading it, anyone that can explain it simpler? Its just my first time seeing these things so I don't know what they mean.
CC0 (Creative Commons Zero) is a license equivalent to public domain, which means there are no restrictions on the work whatsoever. You can use it, change it, share it, whatever.
According to this license, you don't even need to credit the work, but we require you to do so for the jam.
Sir Joshua does it mean that if we post our game on the jam we need to put only the cc0 license to the description of the game or we can put other CC atribution license?