"The Order of Wizards (Quenya: Heren Istarion), or simply Wizards (Q.: Istari), were a group of Maiar sent to Middle-earth by the Valar in the 2nd Age. They were embodied as mostly elderly Men and entrusted to aid the Free Peoples against the threat of Sauron's conquest by lending them their wisdom and counsel. They were originally known as Five Guardians and were members of the Guardians around Cuiviénen.
The Istari became well-known among the various races of Middle-earth over the centuries. Relationships between the Free Peoples and the Wizards varied, however, as the Free Peoples as a whole were unaware of the Wizards' true origins and their true nature as Maiar. Inevitably, questions began to be asked about the Wizards, though no firm answers were ever found.
The Elves most of all strongly suspected that the Wizards were far more than they appeared and, despite their natural form, were certainly not of the race of Men given their preternatural skill in magic and their prodigious physical and mental gifts. As such, the Elves respected and revered the Wizards for their wisdom and power but only to an extent; they were usually disinclined to follow the Wizards' counsel as most Elves still believed themselves superior to the Wizards overall.
Men interacted less with the Wizards. They did not suspect the Wizards of being more than they appeared, as the Elves did, but acknowledged that they possessed power and knowledge beyond the understanding or the reach of ordinary men. They too respected the Wizards and looked to them occasionally for counsel, but were prone to misinterpreting said counsel as commands rather than guidance and disliked the thought of Wizards taking charge in their affairs. The Dwarves and Hobbits had the least amount of contact with the Wizards. Hobbits viewed them as little more than unusual and strange magicians that caused unnecessary trouble, preferring that they remain apart (with the notable exception of the Tooks.
Despite their outward appearance as old men and inability to challenge Sauron directly, the Istari were among the most powerful beings to walk Middle-earth. While they could be hindered, harmed and even killed as with other races, death for them was merely temporary, as they simply returned to the Timeless Halls upon death whereupon the One would send them back to Middle-earth as many times as needed until their task was complete, as was seen with Gandalf's death and resurrection. Once their task was completed, the Istari were to return to the Timeless Halls. Only Gandalf, as a Ring-bearer, was allowed to go embodied to the Undying Lands.
True to their name, the Wizards each possessed incredible magical powers that allowed them to perform astonishing feats; their power was reputedly greater than or, at least, equal to that of the Elves. Each Wizard carried and utilised a powerful staff, through which he channelled and performed most of his spells and magical actions. They could, if needed, use magic independently of their staffs, such as telekinesis and healing. Through their magic, they could cast illusions, shoot firebolts, summon lightning strikes, heal grievous wounds, hurl enemies around with ease, conjure protective shields, disintegrate entire structures and even ensnare the minds of other beings. Yet, for all their power, the Istari were expressly forbidden by the Valar from openly using their magic except in times of great need and as such they (with the exception of Saruman) more often relied on their wisdom, quick-thinking and reasoning skills to overcome challenges..."