Google’s Gary Illyes answered a question about site structure, explaining why a hierarchical site structure is good for SEO and when it’s okay to use a flat site structure. Gary offers a good reason why a hierarchical site structure is a good choice and why the flat site structure is okay for simple websites. Flat Site StructureA flat site structure is when every page has a link from the home page, thus every page is one click away from the home page. Also Known As The Taxonomic Site StructureThe hierarchical site structure was also known as a taxonomic structure in which things are categorized in hierarchical groups. Also Known As The Pyramid Site StructureHierarchical and Taxonomic site structures were also known as the Pyramid site structure.