A
name–value pair,
key–value pair,
field–value pair or
attribute–value pair is a fundamental
data representation in computing systems and applications. Designers often desire an open-ended
data structure that allows for future extension without modifying existing code or data. In such situations, all or part of the
data model may be expressed as a collection of
tuples <
attribute name,
value>; each element is an attribute–value pair. Depending on the particular application and the implementation chosen by programmers, attribute names may or may not be unique.