an internal object that is used to store sparse data compactly in a variable

an object that does two things

a tree structure consisting of individual objects mixed with compositions of objects, that is, objects that have other objects as their children

An object that is formed by two or more objects. The composite object is defined by its parts.

something made up of parts - for example, in the Amsterdam model there are atomic objects (treated as a whole, not decomposed) and composite objects (made up of atomic or other composite objects)

An analytic workspace object that lists dimension-value combinations (also called a tuple) for which there is data. When a data value is added to a variable dimensioned by a composite, that action triggers the creation of a composite tuple. A composite is an index into one or more sparse data variables, and is used to store sparse data in a compact form. See also dimension, sparsity, variable.