Dishonor points are special currency.
You will get dishonor points for killing players of your faction, but only if your level of negative karma (PK points) is really high. If you have small amount of negative karma points you will not get any dishonor points. The more negative karma you get — the more dishonor points you will get for every kill.
More detailed information about how can negative karma will affect your character, read in the specified article «PK system»
You can spend your dishonor points at the Special NPC in the capital of your faction.
Points of battle glory
Except of dishonor points — taking part in PvP-fights you can also get very useful points of battle glory.
Points of battle glory are the additional currency that you get for killing players of the other faction ant taking part in the PvP- events.
When you get enough of these points, go to the special NPC in the capital of your faction, and also in the future in the camps of your faction on the battle territories. From these NPC you can buy equipment and potions for battle glory points.
Have in mind that you can’t sell the items and potions that you get for battle glory points; if you don’t need them anymore, all you have to do is to throw them away.
All merchants sell sets of equipment for all classes. More powerful is the equipment — the higher is the price.