Structural groups determine the attachment mode of fiber bundles and how to transform them in fiber bundles. Fiber bundle is a mathematical theory, which is used to describe complex systems and physical phenomena, and is widely used in differential geometry, topology, physics and other fields.
In the theory of fiber bundle, fiber bundle consists of three main parts: total space, bottom space and projection mapping. Structure group is an important part of fiber bundle and a mathematical group that determines the internal structure and transformation law of fiber bundle.