A vendor is a NPC that buys or sells various game items. Note that some vendors will only sell to members of their faction. Also, not all vendors will buy every kind of equipment - if one vendor refuses to buy an item from you, try going to a different vendor.
Commands
* list - see a vendor's list of goods. * buy - buy an item from a vendor's list * sell - sell an item to a vendor * offer - get an appraisal from a vendor * ask about - have a vendor show you the long description of an item. * retain - 'locks' an item so that you cannot accidently sell it to a vendor. * unretain - unlocks a retained item, so that you can once again sell it to a vendor.