Conductor

Conductor can mean different things in different contexts:

• In science and engineering, a conductor is material which contains movable electric charges in which an electric current can be produced. See also heat conduction.
• In music, a conductor is a person who directs performances; see conducting.
• A conductor is also a person who sells and checks tickets on a bus, tram or train.
• In pseudorandomness, a conductor is a combinatoral object that extracts randomness from weak random sources. It is a generalization of the concept of an extractor.
• In algebraic number theory, the conductor of an abelian extension is an ideal, modulo which the associated characters are defined.