Why using a DB ?

• Provide users with an abstract view and hide complexity
  (how data is stored and created and maintained).
• Provide fast search, insert, etc, using algorithms like trees.
  This is important when DBs are large.
• Combine and filter information.
• Apply functions to data (min, max, etc).
• Convenient DB interfaces to C++, Perl PHP, etc.
• Allow simutanious use of multiple users,
  with user priviliges (permissions).
• Data security: Backups, check data integrity,
  automatically perform consitency checks.