What primarily controls a parametric modeler like SolidWorks?

Parametric modeling in SolidWorks is fundamentally based on the concept of relationships and dimensions. This means that every feature and part of the model is defined by certain parameters, such as geometric relations (like coincident, concentric, etc.) and specific dimensions (like length, width, height). These parameters allow users to create models that are flexible and can be easily modified. For instance, if you change the dimension of one feature, related features can automatically adjust based on the defined relationships, thereby maintaining the integrity of the design.

While curves, angles, materials, textures, shapes, and sizes are all important elements of modeling, they are secondary to the underlying relationships and dimensions that drive the parametric design process. Thus, understanding how to manipulate relationships and dimensions is crucial for effective use of SolidWorks in creating and managing complex designs.