Superman in the wikipedia
The story of Superman’s origin parallels those of other cultural heroes and religious figures such as Jesus, Moses, Gilgamesh, Samson, or Krishna, who were spirited away as infants from places where they were in danger.
In 1986, after the Crisis on Infinite Earths limited series, DC Comics hired writer/artist John Byrne to re-create the Superman character, reshaping the previous 48 years of stories by putting new twists on the established mythos.
The post-Crisis comics present Clark Kent as the “real” person, with Superman as the secret identity that he uses to prevent his enemies from harming his family and friends. People do not suspect that Superman is hiding his real identity because he wears no mask. The concept that Clark is the real man, as well as the greater emphasis on his Earthly upbringing, is a deliberate reversal of the pre-Crisis version. Another significant aspect of Superman’s reinvention is a reduced level of abilities, with powers such as time travel removed completely and other powers — notably his invulnerability and super-strength — vastly reduced. The series also introduces the idea that Superman’s invulnerability stems from his body’s creating an “energy field” when exposed to solar radiation from the Earth’s yellow sun.
In 1992, DC Comics published the storyline “The Death of Superman“, in which Superman fights a character called Doomsday. Both Superman and Doomsday are killed, taking each other down with their final blows. “The Death of Superman” is followed by “Funeral for a Friend”, which chronicles Superman’s funeral and examines other characters’ reactions to the death of the hero. Next, DC published the “Reign of the Supermen” storyline, during which four different characters — a new Superboy, the cyborg “Man of Tomorrow“, the murderous “Last Son of Krypton“, and Steel — are introduced as Superman, although none of them are.