Mechanics has to do with effects and forces, which affect rigid and moving bodies. Mechanics is divided into various areas such as statics, dynamics, kinetics or thermodynamics. We will limit ourselves to two areas: dynamics and statics. Even in the ancient world, scientists studied the areas of mechanics. The old master builders of cathedrals built higher and higher churches that pushed the experimentation with the balance of forces to its limits. Today, a structural engineer does the calculations for the stability of a building. His profession comes from the mechanics subarea of statics. You will learn more about this in the statics part. Whenever machines or gear units are set in motion, they are dynamic. Dynamics describe the change of the movement variables, for example, for the rotation of a shaft, back-and-forth movements or the toothed gear transmission. So dynamics is the science of changes in movements.