A pseudonym (/ˈsuːdənɪm/) (originally: ψευδώνυμος in Greek) or alias (/ˈeɪliəs/) 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. Most pseudonym holders use pseudonyms because they wish to remain anonymous, but anonymity is difficult to achieve and often fraught with legal issues.