A concept is an abstraction or generalization from experience or the result of a transformation of existing ideas. The concept is by all of its actual or potential instances, whether these are things in the real world or other ideas. Concepts are treated in many if not most disciplines both explicitly, such as in psychology, philosophy, etc., and implicitly, such as in mathematics, physics, etc. In use the word concept often just means any idea, but formally it involves the abstraction component.