Units of Measure
Measurement Glossary
Definitions for key terms used in measurement standardization, unit systems, and API design.
unit
The basic quantity used for measurement (e.g., metre, second, gram).
base-unit
A unit defined independently; not derived from other units.
prefix
A factor applied to a unit to scale it (e.g., kilo, mega, milli).
si-prefix
A prefix defined by the International System of Units (SI).
decimal-prefix
A prefix based on a power of 10 (e.g., kilo = 10³).
binary-prefix
A prefix based on a power of 2¹⁰ (e.g., kibi = 2¹⁰). Defined by IEC.
multiple
A unit formed by a positive-exponent prefix (e.g., kilometre).
submultiple
A unit formed by a negative-exponent prefix (e.g., millisecond).
unit-symbol
The abbreviated written form of a unit (e.g., kg, m, s).
unit-name
The full written name of a unit (e.g., kilogram, metre, second).
prefix-unit
A unit formed by combining a prefix with a base unit.
data-prefix
A prefix applied to data-storage units; may be decimal or binary.
api-data-contract
A structured representation of a quantity and unit in an API payload.
unit-interoperability
The ability to exchange unit-bearing values between systems unambiguously.
ucum
Unified Code for Units of Measure — a formal coding system for units in electronic data exchange.