A moderator's number one priority is keeping the server running smoothly. They fix grief, answer any questions a player might have, control chat, and settle disputes. Moderators must be well-tempered, patient, kind, helpful, and have to be extremely familiar with how the server works. However, moderators also are expected to participate in behind-the-scenes server development, whether that be providing opinions in the staff chat about new features or how to reform an old one, relaying feedback about how the server can improve from a player's perspective, and many other development related tasks. You must also be very active in the community and plan to continue that trend into the foreseeable future.
Good luck to all those that apply, and may the odds be ever in your favor... :)