Administrators, also known as moderators and sysops, are distinguished members of the community recognized with additional powers and authority. They are mostly regular content editors and contributors, although some specialize in other areas such as programming. Generally these are the people to go to if you have questions around the site as a veteran or newcomer, want to discuss policy or templating, or need a dispute settled. They are elected through the requests for user rights system. There is also a help guide for newer administrators. I know most of them, they're generally pretty nice guys.