Secret identity

A secret identity is a person's cryptonym, incognito, cover and/or alter ego which is not known to the general populace, most often used in fiction. Brought into popular culture by the Scarlet Pimpernel in 1903, the concept was widespread in pulp heroes and is particularly prevalent in the American comic book genre, and is a trope of the masquerade.

In American comic books, a character typically has dual identities, one overt and one covert. The false or public identity being known to the general public as the "superhero persona" and the other being the secret identity. The private or secret identity is typically the superhero's legal name, true identity, and/or "civilian persona" when they are not actively assuming the superhero persona. It is kept hidden from their enemies and the general public to protect themselves from legal ramifications, pressure, or public scrutiny, as well as to protect their friends and loved ones from harm secondary to their actions as superheroes.

Example

 * Bruce Wayne's "playboy billionaire" is portrayed in all media as his "mask", or false identity, while his Batman persona is his "face", or true identify.
 * Clark maintains three separate identities: the reporter Clark Kent and the superhero Superman identities each allows different means of helping people. These identities are kept separate from his Smallville farmer identity, in order to protect his family's privacy.
 * Danny Fenton maintains two separate identities: the teenage boy Danny Fenton and the superhero Danny Phantom identities allows different means of fighting crime and helping people; these identities are similar to Spider-Man.
 * Kit Taylor maintains his human identity and the superhero Kamen Rider: Dragon Knight identities each allows different means of helping people. These identities are kept separate in Kamen Rider: Dragon Knight.

Occasionally, this trope is inverted. Examples of this are:
 * Marvel Cinematic Universe films Iron Man (2008), where the film ends with the lead character declaring to the world “I am Iron Man”
 * Spider-Man: No Way Home (2021), where it ends with Peter Parker's civilian persona being permanently erased from the memory of the entire world, as a result of a spell by Doctor Strange.