Dual

Dual or Duals may refer to:

Paired/two things

Dual (mathematics), a notion of paired concepts that mirror one another
- Dual (category theory), a formalization of mathematical duality
  - see more cases in Category:Duality theories
Dual number, a number system used in automatic differentiation
Dual (grammatical number), a grammatical category used in some languages
Dual county, a Gaelic games county which competes in both Gaelic football and hurling
Dual diagnosis, a psychiatric diagnosis of co-occurrence of substance abuse and a mental problem
Dual fertilization, simultaneous application of a P-type and N-type fertilizer
Dual impedance, electrical circuits that are the dual of each other
Dual SIM cellphone supporting use of two SIMs
Aerochute International Dual a two-seat Australian powered parachute design

Dual (brand), a manufacturer of Hifi equipment
DUAL (cognitive architecture), an artificial intelligence design model
DUAL algorithm, or diffusing update algorithm, used to update Internet protocol routing tables
Dual language, alternative spelling of the Australian Aboriginal Dhuwal language
DUAL table, a special one-row and one-column database table
Dual-Ghia, US-brand of luxury-car of the late 1950s

Dual (2008 film), a 2008 western drama film
Dual (2022 film), a 2022 science fiction thriller film
"Dual" (Heroes), an episode of Heroes
Dual! Parallel Trouble Adventure, an anime series
Dual (album), an album of traditional Scottish and Irish music recorded by Éamonn Doorley, Muireann Nic Amhlaoibh, Julie Fowlis and Ross Martin, released 2008
Dual (EP), a 2013 EP by Sampha
Duals, an album by U2
The Duals, American duo