The word unit can mean more than one thing:
This is a disambiguation page. If you arrived here by a link from another page, you may want to fix it. If you know any more meanings of the term 'unit' you may want to add them to this list.
- In most physical contexts, 'unit' is used to mean a physical unit.
- A currency is a unit of money (a monetary unit).
- In mathematics, 'unit' often refers to the number one in some sense:
- A unit vector is a vector with length 1.
- The unit circle is the cirle with radius 1 centered at the origin of the coordinate system.
- The unit interval is the interval of all real numbers between 0 and 1.
- The imaginary unit of complex numbers is the number i, a number whose square is -1.
- A root of unity is a complex number a power of which is 1.
- A unit of a ring is an element of the ring that is invertible with respect to the ring multiplication.
- In science and engineering, 'unit' refers to the form of measurement of a quantity. These systems are typically characterized by the units chosen for mass, distance, and time. Unit systems include
- SI (mks), the most commonly used units worldwide
- cgs, derived from SI and also commonly used worldwide; also one of two standard unit systems in astronomy
- imperial units (inlbs), also known as British units, were historically used in Britain and are similar (but not identical) to the current day
- U.S. customary units, primarily used in the USA
- Military units:
- Unit 101 was an Israeli special operations unit.
- Unit 731 was a secret military unit of the Japanese army.
- Functional units are components of a system that perform a specific function:
- A multiple unit is a passenger train whose carriages have their own motors.