Couple - Moment of a couple

                 The couple - Moment of a couple

What is the meaning of Couple in (Engineering)  building mechanics? Characterize snapshot of a couple? 

The two equivalent and inverse powers, whose lines of activity are unique, structure a couple, as appeared in Fig. 1.4. 

The couple - Moment of a couple 

The opposite separation (x) between the lines of activity of two equivalent and inverse powers is known as an arm of the couple. The greatness of the couple (for example snapshot of a couple) is the result of one of the powers and the arm of the couple. Scientifically, 

Snapshot of a couple = P X 

A little thought will appear, that two or three does not create any translatory movement (for example movement in a straight line), yet two or three creates a movement of revolution of the body on which it acts.