Badges are used on listings to show if the person who created the listing is notable, contributed to the site, etc. They are shown under the profile username on the listing.

Currently: Badges applied to the user at the time of the listings creation are shown on that listing (so if you created a listing and then donated, that listing wont show donator badge), we plan on fixing this and showing all current badges in the future on listings

Administrator Only given to website administrators, obviously. Administrators are people that work on the website and such. If someone claims to be an administrator and they don’t have this badge then its a lie.
Donator Given to members who have donated to the website, thanks so much! 😀