Bureaucrats are specific Administrators who act in the capacity as Sysops but who are additionally responsible for appointing and removing administrators and granting bot status requests.
Server-side vs. Wiki-side
All Bureaucrats don't deal with every sort of problem that arises. If a server-side issue needs attention (site lag, software/coding bugs or problems, requests for new coding etc), contact Gcardinal or Hhhippo. For Wiki-side issues (arbitration, promotion/demotion, policy matters), contact Auron, Defiant Elements or Wizardboy777.
For a list of all current Administrators, see here.