Everything You Need to Know About 5 Seconds of Summer

Maybe you've seen the name, maybe they're a complete mystery to you, but one thing is for certain: 5 Seconds of Summer are here, and they're huge.

Feel a little behind the curve? No sweat, it's never too late to get into our handy guide, your exclusive map to navigating the boys from down under's world. Here's what you need to know, now:

1. They're Australian. That's right, folks. Like One Direction, these guys aren't from America ... so they have adorable accents.

2. They're super young. Younger than Justin Bieber and 1D. Frontman Luke Hemmings is 19, guitarist Michael Clifford is 19, bassist Calum Hood is 19 and drummer Ashton Irwin is 21.

3. They're not a boy band...sort of. 5SOS refer to themselves as a rock band, because, well, they're a rock band! They each play an instrument and write their own songs. They've collaborated with Busted, McFly and Kaiser Chiefs, and have recently been seen in studio with Good Charlotte's Madden Brothers, Sum 41, Simple Plan, Katy Perry/Kesha songwriter Bonnie McKee and more. But considering them a boy band? That's a point of contention: Pop-punk purists often write them off for their fashion choices and famous friends, while boy band–obsessed girls often aren't familiar with 5SOS' '90s influences. Can they be both? Somewhere in between? Maybe Paramore's Hayley Williams has the answer...

4. They met at school. The band started in 2011 when Hemmings started posting cover videos on YouTube. The others joined after meeting at Norwest Christian College in Sydney, and the rest is history.

5. In the beginning, they weren't perceived well back home in Australia. Teenage pop-punk bands aren't very common in their native Sydney, where underground, alternative music is normally singer/songwriter stuff or metal and metalcore a la Bullet For My Valentine.

6. Most of them are tattooed. Yes, ladies, your new bad boy obsession is here! Luke Hemmings might be the only angel in the crew but it's only a matter of time before that changes, am I right?

7. They're obsessed with late '90s/mid-aughts pop-punk. The guys cite All Time Low, Green Day, Boys Like Girls and Blink-182 as major influences...and have you seen who they're writing with for album two?