Unit

Unit may refer to:

General measurement

 * Unit of measurement, a definite magnitude of a physical quantity, defined and adopted by convention or by law
 * International System of Units (SI), modern form of the metric system
 * English units, historical units of measurement used in England up to 1824
 * Unit of length

Physical sciences

 * Natural unit, a physical unit of measurement
 * Geological unit or rock unit, a volume of identifiable rock or ice
 * Astronomical unit, a unit of length roughly between the Earth and the Sun

Chemistry and medicine

 * Equivalent (chemistry), a unit of measurement used in chemistry and biology
 * Unit, a vessel or section of a chemical plant
 * Blood unit, a measurement in blood transfusion
 * Enzyme unit, a measurement of active enzyme in a sample
 * International unit, a unit of measurement for nutrients and drugs

Mathematics

 * Unit number, the number 1
 * Unit, identity element
 * Unit (ring theory), an element that is invertible with respect to ring multiplication
 * Unit, a tuple of length 0; an empty tuple
 * Statistical unit, a data point on which statistical analysis is performed
 * Unit angle, a full turn equal to an angle of 1
 * Unit circle, a circle with a radius of length 1
 * Unit cube, a cube with sides of length 1
 * Unit fraction, a reciprocal of a positive integer
 * Unit imaginary number, square root of negative 1  $$(\sqrt{-1})$$
 * Unit impulse, an impulse of height 1
 * Unit interval, an interval of distance 1
 * Unit matrix, a diagonal matrix such that all elements on the main diagonal are 1 and all the others are zero
 * Unit round-off, an upper bound on the relative error due to rounding in floating point
 * Unit set, a singleton, a set with exactly 1 element
 * Unit sphere, a sphere with a radius of length 1
 * Unit square, a square with sides of length 1
 * Unit vector, a vector with length equal to 1
 * Unit type, a type allowing only one value in type theory

Computing

 * Central processing unit, the electronic circuitry within a computer that carries out the instructions of a computer program
 * GNU Units, a software program for unit conversion
 * Rack unit, a unit of measure most commonly used to define the size of certain computing equipment
 * Unit testing, a method by which individual units of source code are tested

Business

 * Stock keeping unit, a discrete inventory management construct
 * Strategic business unit, a profit center which focuses on product offering and market segment
 * Unit of account, a monetary unit of measurement
 * Unit coin, a small coin or medallion (usually military), bearing an organization's insignia or emblem
 * Work unit, the name given to a place of employment in the People's Republic of China
 * Telephone card unit. When bought contains a certain amount of units, which make up their own currency for making telephone calls, that may not necessarily correspond to the monetary cost of the actual telephone card.

Military

 * Active service unit, the former Provisional Irish Republican Army cell
 * Military unit, an homogeneous military organization whose administrative and command functions are self-contained
 * Sayeret Matkal (The Unit), the Israeli special forces unit

Arts and entertainment

 * UNIT, a fictional military organization in the science fiction television series Doctor Who
 * Unit of action, a discrete piece of action (or beat) in a theatrical presentation

Music

 * Unit (album), 1997 album by the Australian band Regurgitator
 * The Units, a synthpunk band

Television

 * The Unit, an American television series
 * The Unit: Idol Rebooting Project, South Korean reality TV survival show

Other uses

 * Unit of alcohol, a measure of the volume of pure ethanol in an alcoholic beverage
 * Unit (housing), a self-contained suite of rooms within a set of similar dwellings
 * Unit, course credit at a school or other educational institution
 * Multiple unit, self-propelled train carriage capable of coupling other units of the same type
 * Head unit, a component of a stereo system mounted inside of a vehicle
 * Unit (Cristian Fleming) (born 1974), electronic musician based in New York City
 * Unit (Norway), a government directorate