leader
Most Kpop groups have a leader, while some chooses not to have one or the company simply didn't assign one as they think it's unnecessary and would like to keep all the members equal. Most of the time the leader would be one of the oldest members or someone who is in between the various ages of the members, and someone who will be able to connect to the older and younger members.
The Leader is expected to be mature and charismatic and be able to handle the attention that is being given to the group. They're expected to keep the harmony and peace in the group, take care of them and help everyone with their problems. They're also the first one who the company would always talk with whenever they have an important announcement.
The Leader is expected to be mature and charismatic and be able to handle the attention that is being given to the group. They're expected to keep the harmony and peace in the group, take care of them and help everyone with their problems. They're also the first one who the company would always talk with whenever they have an important announcement.
vocalists
Main Vocalist
The Main Vocalist is the member who often (but not always) gets a lot of lines to sing in a song, sings the vocally challenging parts, often has the strongest vocal ability and is likely to receive solo parts. There are cases where the Main Vocalist isn't the best technically but maybe has the most unique voice.
Lead Vocalist
The Lead Vocalist usually sings before the Main Vocalist during verses, often sings the chorus (backed by the Main Vocalist), substitute for the Main Vocalist in case of sickness, injury etc.
(sub) Vocalist
The Sub Vocalist or just Vocalist supports the Main and Lead Vocalist and only gets a few lines of the song. In a group with numerous members there are often several Sub Vocalists and/or Lead Vocalists and even several Main Vocalists.
rappers
main rapper
The Main Rapper gets most of the rapping parts, supposed to be the one with the best technique and rapping skills. Most Main Rappers (or any rappers) in groups are only trained to be a rapper or "talk fast" and don't have the technique and the skills, which is why underground rappers don't see idol rappers as real rappers but there are some groups who have "real rappers" in them.
lead rapper
The Lead Rapper usually begins rapping parts, skills are also good, but they're 2nd to the Main Rapper. They supports the Main Rapper and substitute for them in case of sickness, injury etc.
(sub) Rapper
The Sub Rapper or just Rapper is the third rapper of the group, they're not as good as the Lead or Main rappers and in some cases they're just given the position because the group needs another rapper or simply for the reason that there are "no available" position left for them. In some groups there could be no Lead but just a Sub and Main.
dancers
main dancer
The Main Dancer is expected to have great dancing skills and techniques. They sometimes focuses less on singing and are just considered as sub vocalists as they need to save their breath in order to dance, they also get solo dance parts most of the time.
lead dancer
The Lead Dancer is expected to support the Main Dancer and Lead the others when dancing as a group. Some groups hardly dance or don't dance at all so they don't have these positions.
visual
The Visual is believed to be the prettiest one out of the other members in accordance to the Korean beauty standards, likely the one out of the group to appear the most in commercial ads and appear in most variety shows. They're also the actors and actresses of the group. International fans might not agree with this positions as this is purely based on Asian beauty standards therefore having different taste and would disagree with the girl or boy who is assigned to this position. A group may have one or even a couple of visual. The Visual is also often confused with the Face of the Group.
face of the group
Face of the Group is usually the most popular and the most well known member out of the group. They are the member that you would always think of whenever the group's name is mentioned. They're often confused to the Visual because both positions mostly share the same "jobs" that comes with it, they're likely to appear in most commercial ads, the actors and actresses of the group and appear in most variety shows; both are also usually really pretty/handsome. Sometimes both the Visual and the Face of the group could also be the same member.
center
The Center position is still being argued today, most believe that the position don't exist and that the position is included as one of the Face of the Group's job, while some argue that it does exist and that it's another position. The Center's job is basically to be in center of everything, photo shoots, dance line-up etc. Some groups have an even number of members so they wouldn't even have this position.
maknae
Maknae is Korean for the youngest, this is not an actual position but the word is use a lot in Kpop. It just simply means the youngest member of the group.
4d
4D meaning 4-Dimensional is not an actual position just like being the maknae, but it's a personality. 4D means, being the weirdest but cute, funny and unique member of the group, it's not an insult but more of a compliment that the fans give to them. A group usually have one or two members who are given this title by the fans. In some cases some idols have been called 8D because of their out of this world personality. 4D and 8D members are usually called aliens by the fans.
Sub Groups
Sub Groups are smaller groups that make up a big group, but instead of promoting together as a big group, they debut or promote separately, some sub groups are created to promote in different languages and countries. It can also be a group that is created when a member or a couple members are temporarily away and can't join the promotions.
sub units
Sub Units are groups within the group, it consists of small number of members from the "big group". It's usually created to try an alternative music style the main group's concept. A sub unit might also be made up of members from two different groups. A group can have as many amount of sub units depending on how many members the group actually have.