Ballroom dance, refers collectively to a set of partner dances, which originated in the Western world and are now enjoyed both socially and competitively around the globe. Its performance and entertainment aspects are also widely enjoyed on stage, in film, and on television. It is for young and old. While historically ballroom dance may refer to any form of formal social dancing as recreation, with the eminence of dancesport in modern times the term has became much narrower in scope, usually referring specifically to the International Standard and International Latin style dances . In the United States, two additional variations—"American Smooth" and "American Rhythm"—have also been popularized and are commonly recognized as styles of "ballroom dance". ***********The term "ballroom dancing" is derived from the word ball, which in turn originates from the Latin word ballare which means "to dance". In times past, ballroom dancing was "social dancing" for the privileged, leaving "folk dancing" for the lower classes. These boundaries have since become blurred, and it should be noted even in times long gone, many "ballroom" dances were really elevated folk dances. ************************* The definition of ballroom dance also depends on the era. Balls have featured Minuet, Quadrille, Polonaise, Pas de Gras, Mazurka, and other popular dances of the day, which are considered to be historical dances. Today, the term applies to any one of the several dances in which two individuals, a "leader" and a "follower," dance with physical contact through their upper or lower bodies, or simply their arms depending on the particular variety of dance. Since most social dancing is unchoreographed, this contact is necessary for the leader to communicate the next dance move to the follower, and for the follower to respond to this insinuation. This stands in stark contrast with the style(s) of dance seen in clubs and other social gatherings where physical contact tends to be optional and the individuals in question can move freely without any such restraints imposed by firm physical contact or by the necessity to follow the rhythmic pattern present in the music. Some knowledge of known step patterns is essential for both the leader as well as the follower for ballroom dancing. As most ballroom style dances require some knowledge and practice, they have lessened in popularity among the public in the recent decades. Dance historians usually mark the appearance of the twist in the mid 1960s as the end of social partner dancing.**********************Classic and vintage dance societies are dedicated to the performance and preservation of ballroom dances of the past, including older versions of current dances (and this format may also include dances of the present that were done the same way in the past). These companies perform at special events attired in traditional dance costume. Some instructors specialize in the dances of one place or time, or in fad dances: short-lived, time-specific dances that may be associated with the music or style of an era (such as the twist) or a particular song (such as YMCA or La Macarena).