Parts

As a noun, a part is a section of a greater whole. It is normally an intentional segment rather than one caused by dissection. See e.g. Standard Industrial Classification for various categories.

As a verb, to part means to divide or separate.

In the performing arts

Music

In music, a part is the line of music played by an individual instrument or voice (or group of identical instruments or voices) within a larger work. It also refers to the printed copy of the music for each instrument, as distinct from the score, which holds the music for all instruments. For example in a string ensemble you would have separate parts for Violin 1, Violin 2, Viola and Cello, even though there might be several of each instrument (and therefore several copies of each part).

See also: voice, ensemble, polyphony, counterpoint.

Film, theatre and television

In film, theatre and television, a part is an actor's role.

In dance

A part is a dancer's role, particularly in a major work such as a classical ballet.

In mathematics

A part is any geometric object such as a point, line, arc, circle, polygon, polyhedron, or polytope that can be joined together to form a whole. It may also be defined as a bounded region in the plane, for two-dimensional geometry, or as a bounded region in space, for three-dimensional geometry.

There are two kinds of parts: complex and simple. Complex parts can be dissected into simple parts, and simple parts cannot be dissected further.

"Imaginary part" is a common but somewhat odd term, because although it provides part of the information about a complex number, it is not a part in the normal sense.

In fashion

The part of a person's hair is the "watershed" line at which the hair is parted, or divided. Some people part their hair in the middle (a "center part," following the natural part of the hair), and some part their hair at one side or the other. See also: hairstyle.