Members of the site each have a user profile and can upload research output including papers, data, chapters, negative results, patents, research proposals, methods, presentations, and software source code. Users may also follow the activities of other users and engage in discussions with them.
Here is the official word from Microsoft TechNet, The C:\Users folder is shared when any sub folders from C:\Users\<username>\ is shared. The article is stale and mostly unhelpful, but worth knowing to complete the story.
Microsoft Exchange public folders. Public folders are a feature of Microsoft Exchange that are used to share information with others within your organization. Public folder administrators can set privileges for users to access a folder, or the folder can be made available to everyone within your organization.