A pseudonym (; ) or alias () is a fictitious name that a person or group assumes for a particular purpose, which differs from their original or true name (orthonym). This also differs from a new name that entirely or legally replaces an individual's own. Many pseudonym holders use pseudonyms because they wish to remain anonymous, but anonymity is difficult to achieve and often fraught with legal issues. Scope Pseudonyms include stage names, user names, ring names, pen names, aliases, superhero or villain identities and code names, gamer identifications, and regnal names of emperors, popes, and other monarchs. In some cases, it may also include nicknames. Historically, they have sometimes taken the form of anagrams, Graecisms, and Latinisations. Pseudonyms should not be confused with new names that replace old ones and become the individual's full-time name. Pseudonyms are "part-time" names, used only in certain contexts – to provide a more clear-cut separation between one's private and professional lives, to showcase or enhance a particular persona, or to hide an individual's real identity, as with writers' pen names, graffiti artists' tags, resistance fighters' or terrorists' noms de guerre, and computer hackers' handles. Actors, voice-over artists, musicians, and other performers sometimes use stage names, for example, to better channel a relevant energy, gain a greater sense of security and comfort via privacy, more easily avoid troublesome fans/"stalkers", or to mask their ethnic backgrounds. In some cases, pseudonyms are adopted because they are part of a cultural or organisational tradition: for example devotional names used by members of some religious institutes, and "cadre names" used by Communist party leaders such as Trotsky and Lenin. A collective name or collective pseudonym is one shared by two or more persons, for example the co-authors of a work, such as Carolyn Keene, Erin Hunter, Ellery Queen, Nicolas Bourbaki, or James S. A. Corey. Etymology The term pseudonym is derived from the Greek word "" (pseudṓnymon), literally "false name", from (pseûdos) 'lie, falsehood' and (ónoma) "name". The term alias is a Latin adverb meaning "at another time, elsewhere". Usage Name change Sometimes people change their names in such a manner that the new name becomes permanent and is used by all who know the person. This is not an alias or pseudonym, but in fact a new name. In many countries, including common law countries, a name change can be ratified by a court and become a