A given name, in Western contexts often referred to as a first name, is a personal name that specifies and differentiates between members of a group of individuals, especially in a family, all of whose members usually share the same family name (surname). A given name is purposefully given, usually by a child’s parents at or near birth, in contrast to an inherited one such as a family name. A given name is sometimes legally changed through a name change. Given names are often used in a familiar and friendly manner in informal situations. In more formal situations the surname is used instead, unless it is necessary to distinguish between people with the same surname. The idiom „on a first-name basis” (or „on first-name terms”) alludes to the familiarity of addressing another by a given name. The western style of having both a family name (surname) and a given name is far from universal.