A comeback, in terms of publicity, is a return by a well-known person to the activity in which they initially obtained their fame.
For the debut single, acts will have an overall "concept", a marketing hook, which influences the name of the act, clothes, choreography, catch phrases and how they are presented; within bands individual members will have a personal concept, this being a role that they will play within the band, e.g. leader, visual, maknae, rapper etc.
In sports, a comeback occurs where an athlete or a team returns to success after a period of poor performance or inactivity.
... Comebacks in individual sports like tennis, boxing, or golf occur more commonly than in team sports, as athletes in these games have more control over their destiny".
[2] A politician may make a comeback after having left public life, either voluntarily or through loss of an election.