From WoWWiki

A Non-Player Character" (NPC) is any character you encounter and interact with in World of Warcraft that is not controlled by other human players - they are generated and controlled by the game server.

Typical examples of NPCs include Flight Masters, Quest Givers, Vendors, Trainers, and Guards.

Friendly NPCs will have a bag (, if a vendor) or talk bubble (, if you can talk to them) cursor when you mouse-over them. Some vendors require you to talk to them first.

Pointers for talking:

in range to talk out of range

Hostile NPCs are sometimes categorized with other creatures or monsters (aka "Mobs").

Pointers for fighting:

in range out of range

They can be contrasted with Player Characters (PCs, or sometimes just "Players").

[edit] See also

• NPCs category