Kal-El for example, has two different identities, one being Clark Kent, his human alter ego and the other being Superman, a superhero from the planet Krypton. He keeps the truth about his identities a secret by altering his appearance, so that people will believe they are two different persons. As Clark, he wears glasses, and he slouches, making him appear shorter. He also acts like a bit of a clumsy fool. And unlike his partner Lois Lane, he is less likely to take risks getting a story, and he may pretend to be afraid, and run off so he can transform into Superman without her or anyone else noticing.
Clark Kent may be his real name, but he's hardly the real person. Clark Kent is just an act, at least it was ever since he decided to be a superhero. His Superman persona represents everything he truly is, so one could say that is his true identity. With Batman, it is similar. As Bruce Wayne he portrays himself as a rich playboy, but as the Caped Crusader, his true self comes out.
The concept of a secret identity is a very important to superheroes and supervillains trying to have a normal life while out of costume. Lex Luthor is a unique case however, as he doesn't have a secret identity in the traditional sense, but he is a villain, just not in the public eye. He portrays himself as a legitimate businessman at his company LexCorp, but in reality, that couldn't be further from the truth. He uses deception to fool people, and in some ways, it works better than wearing a mask.
Characters with secret identities
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