"Start shrieking, ladies," says Dodai Stewart at Jezebel. "Boybands are back." Fast-rising British quintet One Direction released their debut album, Up All Night, in the U.S. on Tuesday, and for the first time since tween fans launched groups like N Sync, the Backstreet Boys, and 98 Degrees into the pop music stratosphere over a decade ago, the record has the potential to be an unironic smash hit. Joining One Direction in the recent boyband renaissance is fellow British sensation The Wanted. Given the success of these U.K. imports, is it safe to say, "The boys are back?" Here, a guide:

Who are these boybands?
The Wanted, described by Steve Knopper at Rolling Stone as "a quintet of hunky Irish-British dudes who sing romantic party music," is breaking out with their club-ready single "Glad You Came." (Watch the music video below.) The track was featured on the most recent episode of Glee, has sold 206,000 copies, topped the U.S. iTunes singles chart, and its video has logged more than 36 million YouTube views. The group is "teen-dream-ready," says Stewart, with their "clean-cut ethnically ambiguous good looks and frighteningly perfect eyebrows."

What about One Direction?
One Direction's buzzy first single "What Makes You Beautiful" debuted three weeks ago at number 28 on the Billboard Hot 100 singles chart, marking the highest debut for a British act in nearly 15 years. (Watch the music video below.) The group recently booked a coveted musical guest spot on the upcoming April 7 episode of Saturday Night Live, which is "guaranteed to boost the popularity" of the group in the U.S., says Maria Mercedes Lara at Wetpaint, and their debut album Up All Night is "expected to debut at No. 1" this week. The band was formed when its five members auditioned for the U.K. version of The X Factor in 2010. They'll be "taking their clear skin, floppy hair, and tight trousers to the Today show next week," says Stewart, and are currently on tour with Nickelodeon stars Big Time Rush.

Is their music any good?
One Direction scored a huge upset last month at the 2012 BRIT Awards, the U.K.'s version of the Grammys, when they defeated Adele to win "Best British Single" for "What Makes You Beautiful." The song is "the real deal," says Jason Lipshutz at Billboard, and is as "endlessly playable as [N Sync's] 'Bye Bye Bye' or [the Backstreet Boys'] 'Everybody (Backstreet's Back)'" ever was. More than that, Up All Night as a whole "demonstrates an originality in sound that was necessary for the revitalization of the boy band movement." The Wanted's smash "Glad You Came" is "summery dance jam straight from the shores of Ibiza," says Grady Smith at Entertainment Weekly, and should become this summer's "radio-club titan."

Are other bands joining the movement?
Korean pop music, referred to as K-pop, is "crossing over into American markets," says Aylin Zafar at TIME, bringing with it boybands like Big Bang. The group has plans to work with Chris Brown and super-producer Swizz Beatz, and is already so popular internationally that it beat Britney Spears at the MTV European Music Awards for Best Worldwide Act. Nickelodeon's Big Time Rush has a loyal tween following, while the New Kids on the Block and Backstreet Boys supergroup NKOTBSB continues to tour successfully "thanks to nostalgia-loving fans."

So, is this comeback for real?
If nothing else, One Direction and The Wanted are making a splash, says Stewart. "In the age of raw, raunchy, sexually explicit tweets and iPhone hacks, something light and sweet feels like a pleasant change." Besides, for the younger generation, this boyband renaissance seems "all new and fresh." Plus the music is legitimately good, says Smith. "Glad You Came" was catchy enough to be a smash "with or without the Glee boost." There is, however, at least one person who's dubious that this latest British invasion will take. New Kids on the Block veteran Joey McIntyre tells Yahoo UK, "The odds are against both One Direction and The Wanted — neither of them are going to work in America — and it hasn't happened in 50 years so why now?"

The Wanted — "Glad You Came"

One Direction — "What Makes You Beautiful"

Sources: Billboard, Entertainment Weekly, Jezebel, Metro UK, Prophet Blog, Rolling Stone, TIME, Wetpaint, Yahoo UK