For those who don’t recognize the name, Elseworlds was an imprint designed as a branch of DC Comics in the late 1980s.
It allowed for tons of creative freedom, letting auteurs tell the stories they wanted to tell the way they wanted to tell them — and thanks to the multiverse every idea could still be potentially linked back through various narrative machinations.
Essentially a continuation of what had been previously dubbed Imaginary Stories, the idea behind the brand was as an avenue for writers and artists to use DC characters without having to worry about established continuity.
Interestingly, it was basically the same idea that was employed by DC movies pre-2013, all stories standing on their own, but now that the audience has deeper appreciation and openness for this kind of storytelling, there exists a chance to evolve the concept into something bigger and amazing (and obviously with a focus that extends far beyond just projects about Batman and Superman and their related characters).