Relational database are great for storing and retrieving the current set of data. Updates modify the old values to the new values. The old values are gone - lost, nada, zip, zilch - which makes viewing the history, or timeline, of the data impossible without a special design to store the timeline.
While writing the SQL Server Bible series of books, I developed a free utility called AutoAudit. It's still available on CodePlex. Basically, you run AutoAudit and it automatically builds some pretty advanced history features into almost any SQL Server database. Later, I spent a year building a temporal (time-based) database for a hedge fund in Boston.
Why did we go to such lengths? Because organizations are about relationships, and relationships are about history.