I saw this image posted on Instiz site, a popular and influential online community in Korea that discusses happenings in the Korean entertainment world. According to the posted image, it's a ranking or level of different K-Pop boy groups for this year, 2014. I don't know what was the basis for the ranking or the classification but I'll try to explain it based on my understanding of the Korean language and how Koreans explained it to me. Based on the classifications, it only "measured" the groups' popularity in Korea.
Knowing that there are already a gazillion of K-Pop groups in the market, many groups were not even given a chance to be classified. If you were to add groups in each category, which groups would it be? Do you agree with the classifications or labels ? Do you think your favorite groups got "classified" properly? Please write your comments below.
Out of this world (넘사벽): Shinhwa, GOD, TVXQ, JYJ
These groups are considered to be undefeated, incomparable and were able to stood the test of time. No matter what activities they do it will "always" be successful. Other possible translations for the word could be "the best" "second to none."
Nationwide (전국구): Bigbang, Infinite, B2ST, Shinee
This means that anyone in Korea knows something about the group or that these groups exist. Some Koreans, especially those who are not into K-Pop, may not particularly know the names of each member but they would definitely know that these groups are existing in the idol world. So their scope is "nationwide." Many of the comments under this post says Bigbang should be part of "out of this world" level.
Mania Level (마니아층): EXO, B1A4, BAP, Block B, CNBlue
The word mania is commonly used in Korea. It usually means, person who's very passionate in doing one and only thing. So this could mean that the groups in this classification have very strong fan bases or fandom. They are extremely popular but not everyone knows about them yet. Many commented that EXO should be part of "nationwide" category.
Popularity is in Maginot Line (인기 마지노선): 2PM, Super Junior
This means that the popularity of these groups has gone or going downhill. Many of you may know that Maginot Line was the failed line of defensive fortifications constructed by France before WWII to protect its eastern border. It failed big time as Germany was able to easily invade, outflanking the said line. The term is being used as a reference to something you expected to be effective but turns out to be a failure.
2%: ZE:A, U-Kiss, MBLAQ
This is saying that only 2% of the Korean population knows they exist. Literally or not, it means that these groups are only known to only few people in Korea.
Rising Star (떠오르는별): VIXX, GOT7, Winner
I think the name of the classification itself is already self-explanatory. Many of the comments on the post says BTS should be included in this category.