The Paladin is a Holy Warrior hybrid class. Their primary role is that of a melee fighter and secondary as a healing class. Paladins have the ability to play a variety of different roles, including DPS (Retribution), Tanking (Protection), and Healing (Holy). They can cast auras and blessings that provide useful buffs for other players while withstanding heavy physical damage with plate armor and strong defensive abilities.
The paladins are the virtuous defenders of the weak and tireless enemies of the undead. Mixing elements of the warrior and the priests of the Holy Light, the paladin is a tough melee fighter. The tradition of the Holy Light is unique to a few of the Alliance races and the blood elves of the Horde.
The paladin is a warrior of the Holy Light. He upholds all that is good and true in the world and reviles all that is evil and sinister — especially undead and the Burning Legion. He offers succor to the beleaguered and smites his enemies with holy fervor. He is particularly potent against undead, as these creatures threaten the goodly races and the Holy Light burns them terribly. The presence of any evil is reprehensible to the paladin, but he focuses his efforts on destroying undead and demons. These warriors uphold the tenets of the Holy Light and defend the Alliance from the predations of any threat to their peoples. Found in almost every corner of Azeroth fighting the forces of evil and barbarism, these stalwart warriors of faith ceaselessly uphold their vigil against demonic forces from beyond the Dark Portal. Humans, Draenei and Ironforge dwarves are the most likely to become paladins, as these races revere the Holy Light. Blood Elves known as Blood Knights bend the powers of the Light to their will, though rumour has it they have recently began to use the Light legitimately. The paladin order, also called the Knights of the Silver Hand, grew out of humanity’s culture, and its greatest heroes and fiercest proponents are humans. Ironforge dwarves possess the toughness needed to withstand the onslaught of the paladins’ many enemies. High elves rarely become paladins, though this has changed somewhat, as their Blood Elf brothers and sisters expand the Blood Knight order. Paladins are the embodiments of goodliness and selfless dedication to the protection of their peoples. They help the innocent and punish the wicked. As such, all paladins are of good alignment.
During the Second War, some paladins' eyes glowed with inner power of the Light, such as the paladin Turalyon. This is not the case for all paladins, though it occurs in game with certain paladin armor sets. Some are Retribution Paladins, auradins, or are sun paladins. Some are known as paladin warriors (who sometimes become epic paladin warriors). Some paladins choose to become exemplars, and templars.
Paladins are a holy order of warriors whose purpose is to defend and shepherd the war-torn populace of Lordaeron. The Archbishop Alonsus Faol perceived that the pious Clerics of Northshire, who suffered such terrible attrition in the First War, were ill-suited for the dangers of combat. Along with many of the surviving Clerics of Northshire, he sought those of only the greatest virtue among the knighthood of Lordaeron and tutored them in the ways of magic. Led by the crusading Uther Lightbringer, it now rests upon these Paladins - christened the Knights of the Silver Hand - to heal the wounds sustained in combat and to restore faith in the promise of freedom from Orcish tyranny.
Although the Paladins were once loved and revered throughout the lands of Lordaeron, they have since fallen on into hard times. The entire Order of the Silver Hand was disbanded for refusing to kill innocent townsfolk who were believed to be contaminated by the dreaded Undead plague of the scourge. Disenfranchised and driven from their former homes, the Paladins still work selflessly to protect humanity from the gnawing jaws of evil. Empowered by the Light, these mighty warriors now brandish both warhammer and holy fire in offensive battle against all who would trample the meek and innocent. 
The Knights of the Silver Hand was the original paladin order, the Silver Hand was formed in the Second War and was at its height until the time of the Plague. As paladins were immune to the Plague (and indeed all diseases), many members of the order survived the initial push of the Scourge. Unfortunately, the corrupted Arthas Menethil killed many paladins upon his return (including Uther the Lightbringer), leaving only a scattered few. The Order of the Silver Hand still exists but it's only a shadow of its former glory.
Following the invasion of the Scourge, many of the order's paladins joined a zealous group of followers of the Light known as the Scarlet Crusade. However, many of these Paladins have become fanatical towards their ambition of destroying the Scourge, to the point that those not wearing their colors are deemed as corrupt. After leaving the Crusade, some paladins decided to join the Argent Dawn.
In a World of Warcraft questline, Tirion Fordring vows to restore the original order.
Others fled south, to the Kingdom of Stormwind. The paladin order, still referring to themselves as the Order of the Silver Hand, now thrives under their new leadership at the Cathedral of Light in Stormwind City. Over time, the followers of the Holy Light spread their philosophy to the dwarves of Ironforge who soon adopted the tenets of the order as well.
Code of ConductEdit
A paladin must be of good alignment and loses all light abilities if he ever willingly commits an evil act. Additionally, a paladin’s code requires that he respect legitimate authority, act with honor (not lying, not cheating, not using poison and so forth), help those in need (provided they do not use her help for evil or chaotic ends), and punish those who harm or threaten innocents. While he may adventure with characters of any good or neutral alignment, a paladin will never knowingly associate with evil persons, nor will he continue an association with someone who consistently offends his moral code. A paladin may accept only henchmen, followers or cohorts who are of good alignment. A paladin who violates this code, becomes an ex-paladin, and loses all Light-given abilities and can not train further as a paladin until he atones for his violations.
Paladins don't always have to work within good or neutral organizations as seen by the Scarlet Crusade and others - however, they do have to believe they working for good organizations or have faith that their cause is good and just. They can even be downright evil, Renault Mograine being a good example.
More information can be found on WoWWiki.[]