The main vocal is usually the strongest singer in a group, who sounds most stable while singing and dancing live. The main vocal tends to have the most singing time in songs.
There are usually other people in the group who are also good singers who are given titles like lead vocal, power vocal, romantic vocal, or emotional vocal.
Many idols are simply listed as vocals with no preceding title, meaning they sing as opposed to rapping, but they usually get fewer lines in songs than vocals with specific titles. These idols will mostly be found in the sub-vocal category.
Titled vocals are usually called on in interviews to sing excerpts of the song being promoted. They are sometimes featured in OSTs or duets and collaborations with other artists.
The different types of vocals and the varying level of importance each title has can be a point of hot contention among fans. Here on TKW, all types of vocals are grouped in the same category, but the bio page will indicate which type of vocal each person is based on the agency’s official description.
When an idol introduces her/himself as the main vocal, it means their vocal color is part of the signature sound of the group.