The word unit means any of several things:

Unit (housing), in Australia/New Zealand - a self-contained suite of rooms within a set of similar dwellings.

Units of measurement, a fundamental quantity of measurement

Units (Unix), a command-line computer program that does unit conversion

Units conversion by factor-label, a widely used approach for performing unit conversions

A unit can be a general word for a module or device. For more specific example, see next entry.

Functional unit, a component of a computer system such as the CPU

A unit can refer to a self-contained section of a building (or maybe a structure such as a cabin) meant to be rented or otherwise occupied by a party, such as an apartment or business suite. See Apartment.

In chemical engineering, a unit is a (usually) large vessel or section of a plant in which a unit operation goes on. See Chemical plant#Chemical processes.

Unit of action, a discrete piece of action (or beat) in a theatrical presentation

Multiple unit, a passenger train whose carriages have their own motors

United Nations Intelligence Taskforce, a fictional entity in the ''Doctor Who'' television series

Unit (album), an indie pop album by the Australian band ''Regurgitator''

Unit of alcohol, 10 millilitres of pure ethanol in the UK

In biochemistry, unit is the measure of enzyme activity.

In a 19-inch rack a ''rack unit'' is a standard height of 1.75 inches

Military units, including:

Unit 101, an Israeli special operations unit

Unit 731, a covert medical experiment unit of the Imperial Japanese Army, which researched biological warfare through human experimentation during the Second Sino-Japanese War (1937-1945) and World War II

G-Unit, a hip-hop music group

''The Unit'', a television series

A Strategic business unit

In filmmaking, see second unit.

In mathematics:

Unit vector, a vector with length 1

Unit circle, the circle with radius 1 centered at the origin

Unit interval, the interval of all real numbers between 0 and 1

Imaginary unit, ''i'', whose square is -1

Root of unity, a complex number, a power of which is 1

Unit (ring theory), an element that is invertible with respect to ring multiplication

Unit type, a type that allows only one value

In category theory, there is a natural transformation called the unit from the identity functor to the composition of two adjoint functors

ar:وحدة
ca:Unitat
da:Enhed (flertydig)
de:Einheit
eo:Unuo
es:Unidad
fa:واحد
fr:Unité
hu:Egység
io:Unajo
ja:単位
ko:단위
pl:Jednostka
simple:Unit
sl:Enota
zh:單位