When Superman was seemingly killed, Project Cadmus created a clone to replace him. The clone was an adolescent Superman created from Superman's DNA and the director of Project Cadmus, Paul Westfield's DNA. The clone was nicknamed by Paul Westfield, "Superboy" because of his teenage appearance. Having both Westifeld and Superman's DNA, this makes Superboy half human and half Kryptonian so he only possesses some of Superman's abilities.
Superboy adopts the civilian identity of "Connor Kent" and poses as Clark Kent's teenaged cousin, he then goes to live with Jonathan and Martha Kent in Smallville. Connor Kent attends high school like most kids his age and he tries to fit in with real kids, he also fights crime in Smallville as Superboy!Superman later returned and was revealed to still be alive. Superboy fought crime alongside Superman as his sidekick and was given a Kryptonian name by his mentor, his Kryptonian name was "Kon-El".
Tired of taking orders from Superman, Superboy decided to join the teenage superhero team Young Justice and fought alongside Robin and Impulse.
After Young Justice disbanded, a new superhero team was formed, the Teen Titans. Teen Titans had more members than the old team, Young Justice. Since he was a member of the old team, Superboy joined the Teen Titans.