What kind of topological structures are there? This is a more open question about the best practices for topology. I couldn't find much about it in tutorials. I want to know what kind of topological patterns are used depending on the object that is being represented. I found this topology online where you have six diamond shaped quads ordered in a hexagon. Are there more patterns like this and what are best practices for topological patterns depending on the material you want to represent?
Your example shows geometry with Subdivision Surface algorithm on top.


Subdivision Surface works with quads, and when they're not there, it transforms the geometry.
Your image shows Subdivison Surface applied on top of triangles.