Parallel World

The Steel Ball Run Universe (or SBR Universe for short) is an alternate world created at the end of Stone Ocean where the proceeding parts of JoJo's Bizarre Adventure take place in a different continuity from the original timeline. This universe gets its name from the seventh part of the series to first take place in this new world, Steel Ball Run.

Creation
Stairway to Heaven (Made in Heaven)

Following Enrico Pucci's death, the world experienced another Big Bang caused by the power of his stand, Stairway to Heaven (Made in Heaven)'s ability to create new dimensions. In this new world Jolyne was brought back to life after dying fighting Pucci along with alternate versions of her friends, the only expections being F.F, and Emporio Alnino who retained his memory of the original world.

Steel Ball Run
Steel Ball Run, the seventh part of the series would show the other major changes to the Joestar Family by going back to the late 1800's where the SBR version of Jonathan Joestar is shown to be a completely different person to his original counter-part as he tries to learn how to use the Spin used by his future teacher and close friend Gyro Zepelli as he hopes it could give him his mobility back after being paralyzed from the waist down while also competing in the Steel Ball Run..

JoJolion
JoJolion, the eighth part of the series is set in the year 2011 and shows another SBR counter-part of a past JoJo, this time being Josuke Higashikata as he tries to find clues on his identity as he is suffering from amnesia. Along the way he finds ties to himself and another SBR version of a past JoJo though how they are tied is unknown apart from the fact they have both been fused together causing the creation of a new Stand for Josuke.

Alternate Counterparts
In The Steel Ball Run Universe, There are many characters who were reincarnated in another shape or form. Some being changed slightly, while others drastically & only sharing one distinctive trait or a similar action done to the person. In some cases, many characters could share traits with a original character.

Trivia

 * Erina Pendelton & Josuke Higashikata have the most alternate counterparts, both having six in total.
 * Magenta Magenta is the only SBR character who has an original counterpart who wasn't a human but a Stand.
 * Due to his resemblance and similar clothing to Jotaro (in this case always wearing a hat and never taking it off) as well as using the Ora battle cry Josuke of the SBR Universe could well be the alternate counterpart of Jotaro Kujo as well as Josuke Higashikata from Part IV.
 * Yoshikage Kira of the SBR Universe is the first member to be born into the Joestar family to not have a Jo anywhere in his name and to be named after a past antagonist. Also he is the first Joestar member to have the Stand of a past antagonist; while his original counterpart had Star Platinum instead Kira has Killer Queen.