There are popular idol groups all around us full of talented singers, dancers, rappers and more. As each year passes, dozens of debuts are made by rookie groups hoping make a name for themselves in the music industry. However, among the influx in rookie groups, you can also count on a sub-unit of an already popular idol group to make a new debut of their own. Here's a list of most well-known and popular sub-units.

TaeTiSeo

Comprised of Girls' Generation members; Taeyeon, Tiffany, and Seohyun, TaeTiSeo made their debut with the hit song "Twinkle" back in 2012. TaeTiSeo was Girls' Generation first official sub-unit having both released and promoted multiple tracks from the mini album. TaeTiSeo has their own show, 'The TaeTiSeo', currently airing as they gear up for a possible comeback in the later months of 2014.

Infinite-H

Infinite has had few subunits in the past but one that stood out in particular was Infinite's Hip-Hop sub-unit, Infinite-H. Infinite-H consists of Infinite's resident rapper duo, Hoya and Dongwoo. The unit made their debut as the official first sub-unit of Infinite back in 2013 with their mini album, 'Fly High'. Infinite-H went on to promote their title song, "Special Girl" alongside Bumkey.

Orange Caramel

When on the conversation of sub-units, who could leave out After School's bubbly and fun, Orange Caramel? Orange Caramel can strongly say that they are one of the more unique sub-units of the bunch. Their mother group, After School, tends to focus on specialized and sexy performances while Orange Caramel continues to be a stark contrast. Orange Caramel's music is funky, fun, colorful and definitely catchy. Orange Caramel is already four years into their success having debuted back in 2010 with their first single, "Magic Girl".

SISTAR19

Comprising themselves of Sistar's rapper and power vocal, Bora and Hyorin formed the duo in 2011 less than a year after their home group SISTAR's debut in 2010.  Who could forget the body wave from their first single "Ma Boy"? SISTAR19 drew in their crowd with their sexy moves and strong voice garnering them a lot of favorable attention.

Super Junior

On most occasions, idol groups tend to have about one or two sub-unit groups on average. Super Junior, on the other hand, went above and beyond having a grand total of five sub-units since their debut in 2005.

Super Junior-K.R.Y: Super Junior's ballad trio consisting of Kyuhyun, Ryeowook, and Yesung

Super Junior-T: The Trot unit with LeeTeuk, Heechul, Kangin, Shindong, Sungmin, and Eunhyuk

Super Junior-H: 'H' meaning 'happy' with members LeeTeuk, Yesung, Kangin, Shindong, Sungmin and Eunhyuk

Super Junior-M: A Mandarin-language sub-unit with members Zhou Mi and Henry added to the bunch.

Donghae & Eunhyuk: The popular duo Donghae and Eunhyuk have successfully promoted various hits in both Korea and Japan

Bonus:

Though this group doesn't have an official sub-unit name, these five boys warmed our hearts when they promoted back at the end of 2013. EXO's vocal subunit pulled our hearts with the heart wrenching ballad 'Miracles in December'. The vocalists, Luhan, D.O., Chen, Baekhyun, and Lay on the piano made for a perfect unit during the Winter Holiday's. Let's hope to be gifted with another heavenly single from this unit in the future.

Who is your favorite idol sub-unit?