Emblem Gear (WoW)  

The idea behind Emblem Gear, or Badge Gear as it used to be called during The Burning Crusade was to combat the perceived unfairness of random loot drop.

By making each boss drop a token and than letting player spend token to buy gear they wanted from certain npc, players would be ensured that they would eventually get something out of raiding or running 5-man instances. The idea was introduced with Badges of Justice in TBC, was extremely well received with the player base and has now become an integral part of the game.

In Wrath of the Lich King however, the Emblems were tiered further, preventing the situation in TBC where low level instances and raid gave access to high tier quality gear.

Badge of Justice & The Burning Crusade

Badge of Justice would drop from boss fight in level 70 Heroic Instance has well as the raid boss in Karazhan. At the time, farming instance for Badges was seen as the best way to get ready for the raid scenes. At a later date, Blizzard released a new batch of Badge Gear which was way superior to what one could get from Instance or Karazhan, allowing people to get ready for much harder content much faster.

While Badges of Justice and their vendor are still available in the game to this day, those are now legacy content/item.

Emblem of Heroism

Emblems of Heroism are the first tier of token dropped in Wrath of the Lich King - they can be obtained from bosses in the level 80 Heroic instance or from any boss in the the normal version of Naxxramas, Vault of Archivon, Eye of the Eternity or the Obsidian Sanctum.

The Gear from the Emblem of Heroism is fairly good, equal in item level to the epic that drop from the last boss of an Heroic and slightly lower than 10man Raiding Gear. Farming the emblem for those gear allow one to get ready for raid content much faster, or to get an upgrade from some of those harder to get gear slot.

Emblem of Heroism can also be used to buy Frozen Orbs, which make obtaining them and getting those crafted epics much easier.

Among other things, Emblem of Heroism can be used to obtain the hands and chest token of your 10man Tier 7 set.

Every shop in Dalaran has a Vendor who sells a handful of Emblem item, but usually the handiest way to get your gear is simply to go directly to your faction's Emblem Vendor. They can be found in Dalaran, Arcanist Ivrenne, serves the Alliance while Magistrix Lambriesse serves the Horde.

Emblem of Valor

Emblems of Valor are the second tier of token dropped in Wrath of the Lich King - they can be obtained from bosses in the Heroic version of Naxxramas, Vault of Archivon, Eye of the Eternity or the Obsidian Sanctum. As of patch 3.1, they also drop from the bosses in the normal version of the Ulduar raid. Patch 3.1 also increase the number of item that you can obtain with those Emblems.

Emblem of Valor are not currently available to without raiding in some fashion.

Emblems of Valor can also be traded in for Emblem of Heroism if you so wish.

Among other things, Emblem of Heroism can be used to obtain the shoulders and legs token of your 25man Tier 7 set.

Every shop in Dalaran has a Vendor who sells a handful of Emblem item, but usually the handiest way to get your gear is simply to go directly to your faction's Emblem Vendor. They can be found in Dalaran, Arcanist Adurin, serves the Alliance while Magister Brasaelserves the Horde.

Emblem of Conquest

Emblem of Conquest are a new addition to the game with patch 3.1 and can only be obtained from defeating boss in Heroic Ulduar.

The gear from those emblems is much more powerful than gear from the other emblems. Among other things, the Emblems can also be used to buy Runed Orb, which can be used to craft epic items. You can also use them to obtain the head and chest token for your 25man Tier 8 set.

Every shop in Dalaran has a Vendor who sells a handful of Emblem item, but usually the handiest way to get your gear is simply to go directly to your faction's Emblem Vendor. They can be found in Dalaran, Arcanist Firael, serves the Alliance while Magister Sarienserves the Horde.