The term theory means a fundamental set of propositions about how the world works, that have undergone extensive testing and in which we have gained confidence. The synergy between theories, methods, and tools lies at the heart of any field of human endeavor that truly builds knowledge.
Theory stems from the Greek root theo-ros , meaning spectator.
It derives from the same root as theater. Theories are invented to, similar to theater, bring out in public space a play of ideas that might aid in better understanding of our world. Theories are applied through the use of methods and tools. Methods are a set of systematic procedures and techniques used in particular types of issues and problems. Tools are used for the preparation, construction, and execution of specific tasks.