Abstraction in its main sense is a conceptual process by which general rules and concepts are derived from the usage and classification of specific examples, literal (“real” or “concrete”) signifiers, first principles, or other methods. “An abstraction” is the product of this process—a concept that acts as a super-categorical noun for all subordinate concepts, and connects any related concepts as a group, field, or category. Conceptual abstractions may be formed by reducing the information content of a concept or an observable phenomenon, typically to retain only information which is relevant for a particular purpose. For example, abstracting a leather soccer ball to the more general idea of a ball retains only the information on general ball attributes and behavior, eliminating the other characteristics of that particular ball. In a type–token distinction, a type (e.g., a ‘ball’) is more abstract than its tokens (e.g., ‘that leather soccer ball’). Abstraction in its secondary use is a material process, discussed in the themes below.