Trees are hierarchical structures of files and folders that allow users to easily navigate through a website. They are a key element of information architecture and effective user interface design. By organizing information in a clear, easy-to-follow tree structure, site visitors can quickly find what they are looking for.

Creating an optimized tree is a complex task that requires a good understanding of user needs and careful attention to consistency and simplicity. A good tree structure can help improve user experience and increase time spent on site, while reducing bounce rate.