A Concept is one of the abstract building blocks of computing: an algorithm, a data structure, a theoretical result, or a named paradigm or principle that a field defines its claims in terms of, independent of any one language or system that implements it. Recursion, the sorting algorithm, the linked list, the Turing machine and object oriented programming as a paradigm are all Concepts. A Concept is not a Language or a System: a concept is the idea, which a language may express and a system may embody, but the idea itself is prior to and independent of either.