

They're specifically PvP gems whose stats only work on equal-level players. The most popular honor gems are Focus, Resilience, and Toughness. Basically, it's a currency largely derived from PvP. You get honor points by killing enemy players in war zones, participating in faction dailies, PvP events, and arena. They're called honor gems because they're gems you can get from the honor point store (although some can be sold on AH as well). Since you're focusing on PvP, honor gems are what you'll likely spend your time getting.
