Minecraft wiki entry for Server, associated text: Servers are generally managed by administrators and operators. The administrator generally takes responsibility for the server. It may be that the server is running from their machine, or that they simply have jurisdiction over a server. Operators generally assist the administrators to moderate a server and to prevent unruly players and griefers. Both operators and administrators have access to various commands in order to ensure the smooth running of the server. On a default server, players are assigned as operator or administrator by using the /op <playername> command, or by editing the ops.json in the server directory, then restarting the server.