Here's the Updated Map of the Arrowverse Multiverse

Earth-1

The default Earth for The CW, Earth-1 is the home of The Flash, Arrow, and DC's Legends of Tomorrow. This Earth, which is roughly analogous to our real world, is also the home of CW Seed's Vixen and, thanks to in-continuity appearances of John Constantine on both Arrow in previous seasons and Legends this season, may also contain the now-defunct Constantine. New this year to our list of information about Earth-1 is that it appears to be the home earth of Kate Kane/Batwoman, who was introduced in last fall's "Elseworlds".

Earth-2

There's not a lot of new information about Earth-2 since our last look at this version of the world. Earth-2 is still the best-known alternative world for fans of The Flash as it's where Harry Wells hails from. It's also the first Multiverse world that Team Flash has travelled to while trying to deal with the evil Zoom in Season Two. Jesse Quick is now the speedster hero of Earth-2, a situation that led Harry to return to Earth-1. It's also the home of Laurel Lance/Black Siren, who decided to return home last season on Arrow after having something of a redemption on Earth-1

Earth-3

Home of Jay Garrick (John Wesley Shipp), there aren't really a whole lot of updates on this world. Jesse Quick briefly went to Earth-3 to fill in for Jay while he took Wally's place in the Speed Force prison, though we can assume Jay is back protecting his reality after he returned from the Speed Force to help Barry defeat Savitar, though Jay has mentioned that it was time for him to go into semi-retirement and train a new Flash on Earth-3 to take over for him.

Earth-12

During The Flash's fourth season, fans were introduced to a handful of new Earths by way of The Council of Wells. In an attempt to figure out who DeVoe is, Cisco and Harry reached out to various versions of Harrison Wells across the multiverse to create their own think tank in the episode "When Harry Met Harry...." Hailing from Earth-12, Harrison Wolfgang Wells was one of the Wells' to be recruited. Harrison Wolfgang Wells is incredibly smart with four PhDs, and he has even written a book, but had a little bit of difficulty initially working together with the rest of the Council due to his extreme apathy. In Season 5, though, Harrison Wolfgang Wells claimed to be unable to help Team Flash deal with Cicada and instead suggested they reach out to the best detective in the multiverse: Harrison Sherloque Wells.

Earth-13

Consider this the Lord of The Rings or Harry Potter corner of the multiverse. The existence of Earth-13 was revealed when Wells the Grey, a wizard-like version of Harrison Wells, showed up for the Council of Wells but was quickly disconnected by Harry. Not much is known about Earth-13 except for it might be home to magic, considering Wells the Grey reminds us a lot of Gandalf the Grey. We have to wonder, though: are metahumans magic there?

Sadly, we have no new updates on this Earth.

New: Earth-15

A new Earth to the map, Earth-15 is a dead Earth. It's not clear how Earth-15 became a dead Earth, but it has come in handy. In Season 4, Cisco vibed all of Neil Borman/Fallout's nuclear radition to Earth-15. Since then, Earth-15 has been mentioned a few times as an option to send threats from Earth-1, namely a nuclear bomb Team Flash had to stop in Central City and, in Season 5, a virus made from the metahuman cure.

Earth-17

Earth-17 was mentioned during The Flash's third season when Harry sent out a cryptogram into the Multiverse that Harrison Wells of Earth-17 cracked. Based on the appearance of Harrison Wells-17, the world has a steampunk theme, and everyone speaks very formally and has a deeply pronounced English accent.

Earth-19

Earth-19 is the home of two notable characters from The Flash. Cisco's ex-girlfriend Gypsy (Jessica Comacho) is a Collector hailing from Earth-19 and the late H.R. Wells was from that world too. Earth-19 was nearly destroyed by invading hostile forces from an unknown Earth, and, after managing to survive, Earth-19 outlawed inter-dimensional travel for their Earth in an attempt to prevent such a disaster from ever happening again. Now that we've seen how vicious Earth-X is, we can't help but wonder if it was Earth-X that tried to destroy Earth-19.

Earth-22

You can consider this one the Mad Max: Fury Road Earth. Home to Wells 2.0, a cyborg version of Harrison Wells that joined the Council of Wells, Earth-22 is an apocalyptic world with such harsh living conditions that humans have become one with machines in order to survive. Cannibalism is a survival technique on this Earth, and, according to Wells 2.0, those Earth-22 inhabitants who live under the rule of Krug the Face Crusher are not allowed to apologize. Weird information about this Earth? Wells 2.0 apparently ate Earth-22's version of Cisco.

New: Earth-24

Another new Earth introduced thanks to the Council of Wells, Sonny Wells hais from Earth-24, a world VHS technology is still a big deal. It explains Sonny's motto: Be kind. Rewind. It seems like a cool Earth, we just don't know much more about it.

New: Earth-25

Another new Earth introduced due to the Council of Wells, we know very little about Earth-24. What we do know is that H.P. Wells hails from there. This is another Earth we wouldn't mind learning more about in future seasons or as part of Crisis on Infinite Earths.

Earth-38

Home of Supergirl, this Earth has had superheroes for at least a decade and aliens openly live in this world -- even if not everyone is happy they are there. That anti-alien sentiment saw Supergirl ultimately deal with Lex Luthor in Season 4. As in previous seasons, Supergirl has hopped from Earth-38 to Earth-1 to help out as needed, meaning that Earth-38 remains one of the Earths closest to the primary Earth, at least in terms of interaction.

Oh, and it's been officially confirmed that Earth-38 has their own version of Batman.

Earth-47

Home to another of the members of the Council of Wells, H. Lothario Wells, not much is known about Earth-47. The only notable information we have about this corner of the Multiverse is that H. Lothario Wells is the least serious version of Wells we've seen thus far. He has a Hugh Hefner-type appearance, though how much of that is just the character's personality or his world's culture remains to be seen.

Earth-48

An Earth mentioned but not seen, Earth-48 is apparently the home of the unidentified hunter-killer mentioned by Gypsy's father, Breacher (Danny Trejo). Breacher reveals that he fought and killed a hunter-killer from this earth, taking his blade after doing so. In comics, the hunter-killers are known as Forerunner, genetically engineered humanoid creatures created as personal warriors by the Monitors.

New: Earth-51

Earth-51 is among the Earths we know very little about. The world was mentioned in The Flash's fifth season episode "Gone Rogue" as the homeworld of Thaddeus Brown, someone who trained Sherloque Wells in the art of escape.

New: Earth-90

Quite possibly the most exciting Earth introduced in this update, Earth-90 first appeared during the "Elseworlds" crossover as a world ravaged by Mar Novu/The Monitor. The notable thing about his Earth (other than its demise and the great Easter Eggs featured in the stinger scene that kicked off "Elseworlds") is that is more or less officially brings CBS' 1990 The Flash television series into the Arrowverse. Why is that cool? John Wesley Shipp, who played Barry's father, Henry Allen, and Jay Garrick on The Flash starred as Barry Allen in the show's one-season run.

New: Earth-221

Our last new Earth, Earth-221 is the home of Sherloque Wells and while we don't know too much about Earth-221, it appears to be very similar to Earth-1. Some key differences is that there are no Zambonis on that Earth and that winter lasts eight months of the year. The world also doesn't celebrate Thanksgiving, or at least that's what's been implied. Sherloque also sent the love of his life, Earth-1's Renee Adler, to Earth-221 in order to keep her safe from Cicada.

Earth-X

The 53rd Earth. Earth-X is so horrible that, according to Harry Wells, it doesn't even have a designation on the map of the Multiverse. It's so horrific that no one would ever willingly travel there, and as we see in "Crisis on Earth-X", there's a very good reason for that. Earth-X's history follows along with Earth-1's right up until World War II. At that point the paths diverged with the Nazis winning World War II and nuking major world cities. The Nazi control spread, prompting the surrender of the United States, the United Kingdom, and the complete destruction of the Soviet Union. With the help and prompting of Eobard Thawne/Reverse Flash, Earth-X's leader, Oliver Queen/Dark Arrow, and Overgirl invaded Earth-1 to not only conquer it, but also steal Supergirl's heart as Overgirl needed a heart transplant.

While the Earth-1 heroes and Supergirl were able to defeat Dark Arrow and Overgirl and other Earth-X enforcers, the current state of Earth-X is unclear -- though one thing is for certain: there are heroes on Earth-X. It's the home of the Freedom Fighters who are presumably still fighting the good fight.