Borderlands 2 puts an emphasis on the weapon manufacturers, making them a lot more diverse and unique than in the first game. The game is still boasting a high number of guns, promising "a bazillion-er more guns." There are a number of manufacturers in the game, with some returning from the first, and there are some new ones as well. Not all manufacturers will produce all kinds of weapons.
Weapons and equipment can come in a variety of rarities, which usually means it's stronger or might have special properties. White is the most common, green is uncommon, blue is rare, purple is epic, and orange is legendary. There is another types of weapon, E-Tech ones, which are alien weaponry and their names are a deep pink/purple in color.
As of April 2, 2013, Pearlescent weapons returned to Borderlands 2, which are a rarity above that of Legendary. Items with this rarity have a better chance to drop from Badass enemies. Also, another rarity was introduced with the Captain Scarlett and Her Pirate's Booty DLC, which is called Seraph. These are either dropped from Seraph Guardians (which are the Invincible boss mobs in the DLCs) or can be purchased from Seraph Vendors in either Oasis, the Badass Crater of Badassitude, and inside Hunter's Grotto lodge.
In the five years between the first game and this one, Bandits had begun making their own weapons. Bandit weapons are kind of like makeshift weapons, using nuts and bolts are iron sights, or a bottle as a scope. One of the highlights of the Bandit weapons is that they feature very large clips when compared to other weapons. Bandit weapons also have horrible spelling, most likely a nod to their intelligence. Bandit makes Assault Rifles, Pistols, Shotguns, and SMGs.
The weapons from Dahl will resemble contemporary-looking weapons, similar to those featured in modern shooters. These guns do a good job at reducing recoil. Also, when looking down the sights of any Dahl weapon, it will switch to burst-fire mode. Dahl produces Assault Rifles, Pistols, SMGs, and Sniper Rifles.
Hyperion weapons resemble Claptrap, sporting a clean yellow and white look. They are also known to have great accuracy, average-to-good recoil reduction and they are slightly more powerful than other guns from different manufacturers. The longer you fire Hyperion weapons, the more accurate they become. Hyperion produces Pistols, Shotguns, SMGs, and Sniper Rifles.
The weapons from this manufacturer resemble Old West-style weapons in their appearance. These guns deal the most damage, but they have low firing rates and will never have an element attached. Jakobs makes Assault Rifles, Pistols, Shotguns, and Sniper Rifles.
Guns from this manufacturer will sport a futuristic design, and they also pride themselves on always having some sort of element attached to them. Maliwan specializes in Pistols, Rocket Launchers, SMGs, and Sniper Rifles.
Tediore weapons are a special case, as whenever you reload, you throw the weapon and it explodes like a grenade. The damage done by the explosion is dependent on how much ammo was left in the clip when reloading. Tediore makes Pistols, Rocket Launchers, Shotguns, and SMGs.
Torgue weapons trade bullet speed for explosive power, with all shots fired from these guns dealing explosive damage. Torgue manufactures Assault Rifles, Pistols, Rocket Launchers and Shotguns.
Weapons by this manufacturer will carry a Russian vibe, but they all will have minigun barrels as attachments. They will sport the highest fire rate out of all the weapons, but they will also have lower accuracy. Vladof specializes in Assault Rifles, Pistols, Rocket Launchers, and Sniper Rifles.