File systems

Store, retrieve, and update files (program or data) in secondary storage.

Simplify (hide) the overhead required to use secondary storage and standarize 
  the procedure on the user side.

  * Accessing a file on a hard-drive, flash drive, or CD/DVD is the same or
    similar enough that the user can easily adjust their activity.

  Manage storage space management.  Allocate and recover working storage
    blocks as needed.

Over time, the file system protcol added a variety of features.
  
  Storage optimization and access.
    At hardware level - best location of files, defragmentation, etc. 

    At user interface (directories or folder for organization of file names
      by topic or other user valued attribute, displaying icons or partial
      content. )

  Data protection and recovery. (against loss and corruption)

  Data security (against un-approved access, ownership and encryption). 

  Meta-data - data about the data.

    Time-stamp.

    Ownership  (multi-user support)

    Access control. (who can do what with the file)

    Id'ing type of file 
      And associating specific activity or programs with specific data files.

    User defined attributes (author's full name, etc.)

Next