Gigi Hadid and Bella Hadid: Who Are They?

— -- Gigi and Bella Hadid seem to be everywhere these days — Instagram, magazine covers and Taylor Swift videos.

But you're not alone if you have no idea who they are and why and how they got so famous.

The daughters of "Real Housewives of Beverly Hills" star and former model Yolanda Foster and wealthy real estate developer Mohamed Hadid, both are models with burgeoning careers.

And since they don't seem to be going away anytime soon, we've put together this quick primer:

Twins?

Posing in matching lingerie and furs on the latest cover of V — their first magazine cover together — the sisters almost look like twins, but they're not. They are actually a year apart. Gigi is 19 and Bella is 18, and they have a 16-year-old brother, Anwar.

Their mother, who divorced their father in 2000 and is now married to composer David Foster, describes them this way: Bella is the brunette who prefers to wear all black. Gigi is the blonde and bubbly "girl next door."

Men

Different personalities mean they have different tastes in men.

Asked by V if they've ever fought over a potential love interest, Bella said, "No, never. We would never touch the same person."

Gigi chimed in, "We don't have the same type."

Gigi has been linked on-and-off to Australian singer Cody Simpson for over a year, but is currently rumored to be dating Joe Jonas. Meanwhile Bella is reportedly dating Canadian singer-songwriter The Weeknd (real name Abel Tesfaye).

Bella seemed to confirm that she was dating The Weeknd after posting to Instagram a photo of her sister kissing the musician on the cheek after presenting him with the Artist of the Year award at the 2015 Much Music Video Awards in Toronto earlier this week.

Gigi also posted a shot of herself with the musician, calling him "my brother."

Friends

The sisters share some of the same famous friends but also spend time with different pals.

They hang out with another pair of modeling sisters, Kendall and Kylie Jenner. Here they are on their way to Monaco last month:

Gigi is also close with fellow models Lily Aldridge and Cara Delevingne, as well as Selena Gomez and Taylor Swift, whose "Bad Blood" video she appears in.

"She put something like twenty successful women in the industry in her video," Gigi told V. "I felt so lucky to do that because I felt like it was really a sign of our collective willingness to support each other and have each other's backs and kind of hold hands along the way."

Meanwhile, the edgy Bella and Miley Cyrus have become quite the pair.