Meaning of word dynamic

… the high-tech world is, at heart, a cruel, unforgiving place ruled by the merciless dynamics of the marketplace. —Michiko Kakutani, New York Times, 27 June 2002

… my memory of specific events is sketchy, but the general emotional flavor is engraved on my mind as a classic example of my family's bent dynamic. —Florence King, National Review, 15 Oct. 2001

… the Cambrian Explosion, created the evolutionary dynamic that produced most of the species that subsequently populated the earth, from insects and fish to dinosaurs and humans. —J. Madeleine Nash, Time, 20 Aug. 2001

Raisons d'état, not the dynamics of capitalism, created the American thrust for world influence. —Arthur M. Schlesinger, Jr., The Cycles of American History, 1986

the dynamic between a doctor and a patient

Group dynamics are important to consider.

The dynamics of this class are different from those of other classes.