Fans turn on the light stick and wave it during the performance to show support to their favorite K-pop singers/groups.
During joint concerts with other K-pop artists, singers can easily spot their fans as the shape and colors of official light sticks are very distinct.
On the other hand, the artists can feel a sense of pride when they see the stadium filled with their official light sticks all lit up in official colors during their own concerts.
Last year, over 2 million Korean K-pop fans voted on the prettiest official light sticks on 'My Rank'.
K-pop boy groups BIGBANG and SEVENTEEN have won the first and second place by an overwhelmingly majority―each over 30 percent.
After them, boy group BTS ranked third, followed by MAMAMOO, the only girl group that made it on to the top five list.
The fifth one was BTOB, and the five groups after BTOB were EXO, APINK, INFINITE, VIXX and iKON.
Here are the five official light sticks considered the most beautiful, chosen by over 2 million K-pop fans in Korea.
1. BIGBANG (BANG BONG)
2. SEVENTEEN (CARAT BONG)
3. BTS (A.R.M.Y BOMB)
4. MAMAMOO (MOOMOO BONG)
5. BTOB (TRUMPET BONG)
(Lee Narin, Credit= Online Community, 'pledis_17' Twitter, 'myrank' 'ygeshop' 'btsofficialshop' 'bizent' 'cubee' Official Website)