Resurrection is the ability to return to life after having died. It is different from reincarnation in that the affected character is not physically reborn as an infant, but rather, they return to life possessing the same physical characteristics that they maintained prior to being killed. In many cases, resurrected beings also maintain all of the memories they once possessed prior to their death, but this is not always the case.
Death is often transitory in the DC Universe, and not all characters who have returned from the dead necessarily possess this ability as part of their standard repertoire of super-powers. When Superman died for example, he was only able to revive himself due to a photosynthetic reaction to Earth's sun. Even Doctor Occult informed him that such a feat was a one-time-only stunt, and could not be repeated.
One of the more widely known examples of a being with the Resurrection power is Solomon Grundy. Although Grundy is not a "living" being in the conventional sense, he will invariably reform his body no matter how extreme the manner of his demise may have been. Unlike others with this power, Grundy often suffers dramatic personality changes from one life to the next. In one incarnation he may be a savage, murderous brute; in others he may be reborn as an addle-brained man-child.
Another being with this power is Mitchell Shelley – the Resurrection Man. Shelley's ability to revive after death is dependent upon nanotechnology, specifically, microscopic devices implanted in his body known as "Tektites".
Swamp Thing (Alec Holland) possesses a unique application of the Resurrection ability. As the plant elemental of Earth, he can transpose his mental essence into any plantlike material, no matter how remote, even algae. The Swamp Thing generally creates a shell for himself using vegetative material from his immediate environment. If he abandons this shell, or if the shell is destroyed, he can relocate his essence into a new host form.
Resurrection should not be confused with Immortality, which represents a character's ability to live forever without fear of aging or dying.