The Legacy Hero is a longstanding DC tradition. The idea is to take an old character name and concept and rework the character into a new character who may or may not be related to the older one. There’s a bit less of that with the “new 52” today, but when someone opted to rework the Flash from Golden Age Jay Garrick to Silver Age Barry Allen, everything went from there. Furthermore, when Barry met Jay, a character most of Barry’s readers would have never heard of given their age and the collectability of old comics back then, the idea of connecting these old heroes took root and hasn’t really gone anywhere since.
One of the more prolific superhero names for DC has been Starman. Originally, Starman was Ted Knight, an astrophysicist who discovered a way to channel starlight into a small wand he called a cosmic rod (stop giggling, Watson) that allowed him to fly and do stuff with stellar energy (mostly fire energy blasts). Starman was, like many of his contemporaries, a member of the Justice Society and disappeared when the Golden Age of comics ended. Unlike many of his contemporaries, the various attempts to create other Starman characters wasn’t as cut-and-dried as, say, Flash or Green Lantern. There were many Starmen, all with different abilities and few with any relationship whatsoever to Ted Knight.
Post Zero Hour, DC produced another new Starman, this one the son of Ted Knight. Jack Knight had no desire to be a superhero. He was into collectables and ran a small knick-knack shop out of his home town of Opal City. Circumstances pushed him into superheroing, and he probably became the single most memorable Starman of them all.