duality

noun

term in physics, concerning electricity and magnetism
term in electrical engineering
unity of two often opposite but complementary concepts, qualities, aspects or other entities

Pronunciation: /d(j)uːˈælɪti/

Etymology: From Latin duālitās. From dual + -ity.

The quality of containing or comprising two often opposed parts or aspects.
“He was fascinated by the duality of human nature.”
“the moral duality of certain characters”
The aggregate of two complementary subclasses or parts.
“philosophical duality”
“The novel explored the duality of good and evil.”
The mathematical equivalence of two seemingly different theoretical descriptions of a physical system.
“wave-particle duality”
The interchangeability of points and planes.