Thread:Tupka217/@comment-24801547-20140415053159/@comment-1038387-20140415103534

There used to be Earth-Two and Earth-One, home to Jay Garrick and Barry Allen, respectively. Then those got merged in the 1986 event Crisis on Infinite Earths, though Barry died. Wally, the former Kid Flash of Earth-One, took over the mantle of Flash on this new Earth, later designated... New Earth. Wally died too, somewhere. Sort of. It's complicated. Bart Allen (Impulse) became the Flash, then died. Barry Allen came back. Then Wally and his family (Linda Park and his kids Irey and Jai) came back. And then Bart came back. Now, the current New 52 continuity is Prime Earth. Barry is the Flash. Jay Garrick exists on Earth 2. Kid Flash is Bar Torr, a 25th Century former resistance leader in a witness protection program in the past. Wally is probably coming back soon.

Their returning to life has to do with their connection to the Speed Force, a mystical lightning they tap into to run fast. However, the Flashes of Earth-16 (Young Justice's earth) don't tap into it.