A bag is the generic term for any container that a character uses to hold other items. Bags can be placed in the storage slots at the right-most end of the interface bar. Bags inside bags must be empty.
You can purchase extra bag slots for your bank account at progressively increasing rates, starting at 10
for the first slot.
Normal bags can hold any sort of item, unlike special bags that can only hold specific types of items. Special bags give the player more slots to store items, with the tradeoff of only being able to put certain types of items in them. Specials bags are generally cheaper than normal bags of the same size.
Normal Bags
Normal bags come in a variety of sizes and are used to store all the items you obtain through your adventures and come in sizes ranging from 4 to 20 slots:
Ammo Bags
Ammo bags like quivers and ammo pouches can only hold ammunition (arrows or bullets respectively). This makes them less versatile than conventional bags, but they increase your ranged attack speed (10%-15% depending on the item). Ammo bags also tend to be larger than regular bags of the same item level.
Ammo bags can be purchased from Leatherworkers and vendors, or obtained as quest rewards.
Soul Bags
A Soul Bag is a bag used by Warlocks to hold more Soul Shards than they would normally be able to carry in conventional containers.
The soul bag consumes a regular container slot, however, so it reduces the number of available slots for non-Soul Shard items, but contains far more item slots than other bags of equal level. The value of the trade-off is up to the individual Warlock.
Soul Shards harvested by the Warlock are automatically stored in an equipped Soul Bag when acquired, making tedious Soul Shard housekeeping a thing of the past.
Helpfully, soul bags also display the number of soul shards stored within them on the bag icon on the container toolbar.
Note that only Soul Shards can be stored in Soul Bags, and if you wish to convert a Soul Shard into any other type of inventory item (such as a 
[Healthstone] or 
[Soulstone]) you will need extra space in your normal bags.
Craft Bags
There are a number of craft-specific bags that can hold certain materials and products. Like Soul Bags, these are limited in what they can hold but have more slots than regular bags. It appears that all craft bags are Bind on Equip.
| Profession | Holds | Does not hold | Bag types |
|---|---|---|---|
| Enchanting | Dust • Enchanting Essences • Shards • Enchanting Rods • Enchanting Recipes • Motes/Primals | Oils • Elemental Essences • Wands | [Enchanted Mageweave Pouch] • [Enchanted Runecloth Bag] • [Enchanter's Satchel] • [Big Bag of Enchantment] • [Spellfire Bag] |
| Herbalism | Herbs • Blood Scythe | Heart of the Wild • Vials | [Herb Pouch] • [Cenarion Herb Bag] • [Satchel of Cenarius] |
| Engineering | Items Crafted by Engineering • Motes | Ore • Bars • Gems • Cloth | [Heavy Toolbox] • [Fel Iron Toolbox] |
| Jewelcrafting | Mined and Conjured Gems • Jewler's Kit • Simple Grinder • Pearls | [Gem Pouch] • [Bag of Jewels] | |
| Mining | Ore • Bars • Stone • Mining Pick • Motes (Fire & Earth) | Motes (other) • Gems | [Mining Sack] • [Reinforced Mining Bag] |
| Leatherworking | Leather • Skinning Knife • Salt Shaker | [Leatherworker's Satchel] • [Bag of Many Hides] |
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