Red Velvet, the popular girl group formed under SM Entertainment, just achieved a milestone in K-pop that only three other boy bands have earned. They are the first girl group to have four No. 1 albums on the Billboard World Albums Chart.

The first girl group in K-pop to top the world chart four times!

The news of Red Velvet achieving the milestone was first recognized by Billboard themselves on their official website. On Tuesday, November 28, their latest album titled "Perfect Velvet" topped the Billboard World Albums Chart. In its debut week, the nine-track album sold 2,000 copies in the first week ending on November 23.

This marks Red Velvet's best US sales week to date, topping their previous record held by "Red Summer."

This is also the fourth time Red Velvet achieved the No. 1 spot on the prestigious list. Their predecessors include their first full-length studio album "The Red," their fourth mini-album "Rookie," and their summer mini-album "Red Summer." Take note that along with "Perfect Velvet," three of the No. 1 albums released this year alone.

Besides their history of great music, especially the spectacular "Red Summer" from their last album, Red Velvet's featured title track song off "Perfect Velvet" is not only really good but quite unique. The song "Peek-A-Boo" is technically a "Velvet" style song such as "One Of These Nights" or "Be Natural." However, its sound seems to combine elements of their "Red" style songs like "Red Flavor" or "Dumb Dumb."

The unique direction of the song has paid off as "Peek-A-Boo" has earned almost 20 million views on YouTube.

In all fairness, such views may not be a record for K-pop, but the number alone is more than adequate when Red Velvet's competition includes other powerhouse girl groups such as Black Pink and Twice.

Tied with BTS, GOT7, and B.A.P.

As mentioned earlier, Red Velvet is the first girl group in K-pop to have four No. 1 albums on the Billboard World Albums Chart.

The milestone is also held by only three other K-pop acts in which all of them are boy bands. For the longest time, Beautiful Absolute Perfect -- better known as B.A.P. -- had been the sole K-pop act to be on the list. Eventually, Bangtan Sonyeondan (better known as BTS) and Got7 joined them.

Ultimately, Red Velvet having four No.

1 albums on the Billboard World Albums Chart is a sign that K-pop girl groups are catching up with their boy band counterparts internationally. They, along with Black Pink and Twice, are pushing girl groups into the international music scene more so than innovators of girl groups like Girls' Generation, 2NE1, or Kara. And with plenty of new girl groups following behind them, this change will develop even more steam before it slows down.