In aesthetics, style can be roughly divided into various types. In the actual development of art, the same type of style often forms an artistic genre; The development and evolution of various art schools not only constitute the development process of art, but also reflect the changes of social thought and aesthetic ideal in various times.
Geological mechanics noun: limit (restraint, restriction) is a kind of composite structure system, refers to two different periods of tectonic elements, markedly different to each other, ending late structure in the early tectonic complex phenomenon. This phenomenon is due to the limitation of early construction interface. The late construction is called the restricted structure, and the earlier structure is called the restricted structure. Limiting structures can be secondary or primary structures, and most of them are secondary structures. This composite phenomenon is also seen in the vein deposits. The relative period of composite tectonic components can be determined according to the restriction relationship.