Database NPCs are NPCs stored in an NPC Server. They are given a user-defined NPC name (#N) and can warp to anywhere on a server.
NC contains a section for administering Database NPCs, including editing the script, this. flags, viewing Variables and resetting them. This allows an Admin to change things about the NPC which cannot be done in-game without another NPC.
Database NPCs are usually Serverside to be able to function simultaneously with multiple players, warp, use with, etc, so they can work with players and other database NPCs in a collaborative way. Your Database NPC may be used as a Guild Manager, so it needs to interact with the player and server.
Database NPCs can use canwarp/canwarp2 to warp with Level warp Links, and level boundaries on normal Maps. They are also given GMap coordinates when on a GMap (i.e. 120,110 would be 60,50 in level b2).