File systems are the way in which files are named and where they are placed within a computer system for storage and retrieval. A vast majority of operating systems have file systems in which files are placed somewhere in a hierarchal tree structure. Files are placed into a directory or subdirectory at the desired place within the structure.
User interface refers to the means by which the user and a computer interact and communicate by the use of input devices and software. User interfaces fundamentally make the human-machine interaction possible. There are two primary terms to be aware of when acknowledging user interfaces - input and output. Input refers to when users are able to manipulate a system, output on the other hand is allowing the system to indicate the effects of the users manipulation. Examples of input user interfaces include the keyboard, mouse, headsets. Some output are iOS within Macintosh systems and Windows XP on windows.