The druid is a shapeshifting, hybrid class and also one of the most versatile classes in the game. As with other hybrids, druids need to specialize in a single role for the best results. Due to their need to shape-shift to fulfill roles, they can only perform one role at a time; they must switch between the different shapes to adapt to changing situations.
Specialize in damage spells and an additional Moonkin Form. turning them into an efficient ranged spellcaster that is somewhere between a mage and a shadow priest in play style, in the equivalent of plate armor. They excel at nuking single targets as well as providing effective off-healing and crowd-control support. With the Wrath of the Lich King expansion providing them effective AoE damage, they are now on par with any of the other casting classes provided they are skilled.
Enhances the druids abilities in Cat Form. Cat Form specializes in bleeding the target. They have stealth abilities similar to a rogue, and bring versatility to the raid group. Upon choosing the feral specialization some abilities are only available in this tree. Abilities such as Rip and Savage Roar can only be used in this specialization. Other Guardian abilities such as Savage Defense and Bear Hug cannot be used in this specialization.
Enhances the druids abilities in [Bear Form]. Use of Savage Defense to dodge attacks and other cooldowns make the Guardian a very viable tank for Raiding. They are great for encounters that require swapping of tanks to a damage role as all they need is a change of specialization.
Healers. Their resurrection spell Rebirth can be cast in combat. Restoration Druids have some of the best heal-over-time spells of all healing classes, effectively allowing them to continue healing while incapacitated. In addition, the mobility offered by their heal-over-time spells makes them especially effective in PvP. This together with their excellent mana efficiency and in-combat resurrection ability makes them an effective healing class.
A properly specced and geared druid is capable of fulfilling any role. Druid players need to be aware that this versatility also bears a danger — it may be difficult to keep focused when gathering gear. Druids may also encounter doubt from less-experienced players that a class can actually be as flexible as druids can successfully be. In order to truly fulfill a hybrid role, Druids require several complete sets of gear. This is expensive in time, bag space, and gold; however, the ability to spec to completely different roles makes druids a smart and flexible class choice. If you are tired of performing one task, you need not create another character to fulfill another role; you simply respec to a new one at little cost and considerably less effort.
Another nice feature of druids is their ability to travel faster. See the skills section below for more information.
"We are the preservers of the balance, now and forever, as Malfurion lies in the Dreaming. Never forget this." - Kal of Dolanaar
Druids are keepers of the world who walk the path of nature, following the wisdom of the Ancients and Cenarius, healing and nurturing the world. To druids, nature is a delicate balance of actions in which even the smallest imbalance can create storming turmoil from peaceful skies. Druids draw their power from this natural energy, using it to change their shapes and command the forces of nature.  Traditionally druids chose the path of a specific animal totem. Since the invasion of the Burning Legion. however, most druids have undergone a number of reforms, including encouraging the study of magic from all totems. Druids who do this are known as druids of the wild. 
Cenarius is the patron entity of all druids. However, each group of druids has its own special patrons and some even have the ability to transform into a being that looks like their patron. Many druids will take on an animal companion based on their patron.
According to tauren mythology, Cenarius instructed them first in druidism as recounted in their myth. Forestlord and the First Druids . With the release of Wrath of the Lich King, it is strongly suggested that tauren were most likely to have been the first students of Cenarius, as accounted for by a 10,000+ year old immortal tauren druid by the name of Xarantaur. There is still debate whether this character is considered canon, but at the very least Xarantaur suggests in the game that while he and his brethren were taught directly by Cenarius, his fellow druids forgot their lessons over the years; this would imply that current tauren druidism is relatively new, learned from the night elves.
As it stands, the night elves lay claim to the first druid with Malfurion Stormrage. Malfurion
Stormrage, the first of the night elven druids, is not only considered the most powerful known druid in Warcraft lore, but is also considered one of the most powerful characters on Azeroth. Malfurion led the night elves through the War of the Ancients and the long years that followed. With the creation of the World Tree Nordrassil. the kaldorei druids were bound to Ysera and her realm, the Emerald Dream. in which they spent centuries of their immortal lives. The Cenarion Circle was formed as the governing society of druids, based in sacred Moonglade.
Locked in slumber in their barrow dens for generations, the druids awoke to meet the threat of the Burning Legion during its recent invasion. After Archimonde 's defeat, the druids chose to remain in the waking world and help to rebuild their shattered lands. The Legion's attack left a terrible scar on the natural order and the druids sought to heal it.
A depiction of a druid.
Druids come and go as they please, and their goals typically have little to do with the "civilized" world. Unaffiliated with any specific government, the primary druidic organization on Azeroth, the Cenarion Circle, answers to no one save itself. The highest rank that a druid can have is that of archdruid, and there are only a few archdruids on Azeroth. At the moment the Cenarion Circle's leader is Archdruid Malfurion Stormrage, also widely considered to be the first mortal druid on Azeroth.
Strengths, Abilities, and Underlying Motivations
Through their deep connection to life and nature, druids are able to take on an unusually large variety of roles. Probably a druid's best-known role is that of a healer. Druids are justly famed for their ability to restore life, cure poisonous wounds, and remove curses. Indeed, restoring and protecting the planet is one of the top priorities for all druids. Still, to regard a druid as merely a healer is a dangerously simplistic assumption that has led to the defeat of many an unwary foe.
Druids' empathy with the creatures of the wild also allows them to shapeshift into the forms of other animals. For example, a wounded druid whose magical energies are running low might abruptly take on the form of a bear in order to better withstand further injury. Alternatively, the druid might shift into the form of some large cat, sneak up behind an enemy, then pounce and deliver a fierce flurry of melee attacks. Even the deepest oceans can be explored by druids, who can simply shift into an aquatic creature, allowing them to stay underwater as long as needed.
Until the end of the Third War. druids periodically visited the Emerald Dream to monitor the ebb and flow of life on Azeroth. Today such a visit has become more difficult due to Nordrassil's poor health.
Druids possess a deep understanding of the way in which all living things depend upon one another. Whenever this delicate equilibrium is disrupted, the druids work to restore the balance. To that end, druids can use their connection with the Emerald Dream to exert a calming influence over animals, even forcing some into a temporary state of hibernation. Just as the druids can wield peace and somnolence, however, they can tap into the fury of nature itself. Terrible storms respond to their call, thorns sprout from their skin to wound their attackers. Even previously harmless roots grow from the soil at greatly accelerated speeds in order to entangle foes.
For obvious reasons, druids thrive in the wild outdoors. Inevitably they lose some of their effectiveness when they are forced to endure separation from the natural environment. What good is a cleansing rain when a druid cannot even see the sky? How are roots to capture a foe who is standing atop a high tower? Such cases clearly require a druid with the imagination to consider new strategies and the flexibility to carry them out.
Yet this flexibility, too, comes with an underlying negative corollary. The druid tends to be a jack-of-all-trades, but a master of none. An unusual mixture of priest, rogue, and warrior, the druid is therefore not equal to any of these three classes in their particular specialties. Even so, the druid's incredible adaptability serves them well in confronting the challenges which Azeroth throws their way.
Druids do not use shields (although in bear form their armor is so high it were as if they were), and do not dual wield. Off-hand items may be used by druids. Druids receive a 5% bonus to their primary stat when wearing all leather armor. It is uncommon to find two-handed maces with agility on them, so most feral or guardian druids use either staves or polearms.