Components and Parts

In general, a thing's components are its parts; the things that compose it. Components are those identifiable, differentiable and autonomous elements that compose a system.

• In telecommunication and computing, a component is an assembly, or part thereof, that is essential to the operation of some larger assembly and is an immediate subdivision of the assembly to which it belongs. For example, a radio receiver may be a component of a complete radio set consisting of a combined transmitter-receiver, i.e., a transceiver. The same radio receiver could also be a subsystem of the combined transmitter-receiver, in which case the IF amplifier section would be a component of the receiver but not of the radio set. Similarly, within the IF amplifier section, items, such as resistors, capacitors, vacuum tubes, and transistors, are components of that section.
• In logistics, a component is a part, or combination of parts having a specified function, that can only be installed or replaced as an entity.
• In electrical engineering, polyphase AC power systems are analyzed using symmetrical components.
• In manufacturing, a component is an assembly or any combination of parts, subassemblies, and assemblies mounted together in manufacture, assembly, maintenance, or rebuilding.
• For components in mathematics, see connected component (graph theory) (for graphs) or connected space (for general spaces).
• In physics, a component of a vector is its projection onto one of the axes of a coordinate system; for example only the horizontal and vertical components of the movement of a body.
• Somewhat more generally, in mathematics, the components of a tuple are the scalars that are its entries.
• In chemistry, a component is one of the molecular chemical species making up a system. See Gibbs' phase rule.
• In software, the word component has an emerging meaning generalizing the idea of a software pattern, software object, software framework and software architecture. software componentry can be any of these. See also: component software theory, software component. A standard way to implement a component is as a class object (object-oriented programming).
• In thermodynamics, a component is a chemically distinct constituent of a phase of a system.
• In television and video, components are discrete channels for red, green, blue, sync, and sometimes other parts of the video signal (opposite of multiplex or composite video, which has subcarriers for colour). See audio and video connector.
• In arthroplasty and joint replacement surgery components are the terms used for the individual prosthetic elements of the artificial joint. For example, in knee replacement femoral and tibial components are used for the thighbone part and the shin part of the knee respectively.

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.