But in fact there have been many incarnations of the Boy of Steel.
Superboy first appeared in New Fun comics during World War II, when every superhero in the business had a teenage sidekick to appeal to the younger readers. He's the one who got the traditional origin story of the infant Kal-El being sent to Earth from Krypton, and being adopted by elderly farmers Jonathan and Martha Kent.
Originally around ten years old, Kal-El became a teenager for the Superboy comic title, which lasted from 1949 through 1977, with a new series through 1984. Although his adventures should technically take place years ago, no one paid much attention to the timeline until the 1970s, when DC comics made the rule that Superboy stories should always be set about 15 years before the current date..
In 1985, as you may know, the many discontinuities in the DC universe were resolved through the "Crisis on Infinite Earths." Turns out that the various storylines were actually about superheroes from different alternate universes, which were all destroyed. In the new timeline, the only Superboy is Superboy-Prime, from Earth-Prime, whose "S" seems to be on his chest, not on his costume.
But that wasn't the end of the Superboys.
In 1993, a clone of Kal-El appeared, Kon-El, with the secret identity Conner Kent, Clark's cousin. Later he was explained as a hybrid of Superman and archnemesis Lex Luther. Clones, of course, must grow up at a normal rate, and this one promptly became a teenager, dubbed Superboy again.
He died after a fight with Superboy-Prime in 2005, was resurrected in the 31st century, returned to the present, and settled down to civilian life in Smallville.
Then Jonathan Samuel Kent, their son from yet another timeline.