Forgive me if this has been gone over to death, but as I'm working my way through back-issues of DC, I'm wondering about this. I know that there are not only different worlds in the multiverse, but different multiverses! For instance, there was the one that was destroyed in Crisis on Infinite Earths, and then the one that was established post-Infinite Crisis! Yikes!
Here's what I have:
Pre-COIE
Earth-1 - Main hub of DC Comics
Earth-2 - Golden Age heroes
Earth-3 - Crime Syndicate, villainous versions of Earth-1 heroes.
Earth-4 - Charlton comics characters
Earth-S - Marvel Family. Not sure if other Fawcett Comics heroes also occupied this Earth, like Bullet Man
Earth-X - World where WWII raged into the 1980s, where the Freedom Fighters migrated.
Earth-6 - Lady Quark's home, only established in COIE
Post-IC
New Earth - Main hub of DC Comics
Earth-2 - Reincarnation, so to speak, of Earth-2 from previous Multiverse.
New 52
Prime Earth - Main hub of DC Comics.
I know next to nothing about DC post-2011, so I'm not sure if Flashpoint reset the Multiverse, or just New Earth/Prime Earth.