THE RELATIONAL DATA MODEL

This model was defined by Edgar F. Codd in 1970.  Codd
was working at IBM Palo Alto Research Center.  He based
his model on Relational Algebra and Relational Calculus.

His concern was for "data integrity" which focused on 
preventing "dirty data" with traits such as:
fragmentation: related info not linked
redundancy: same info kept in more than one place
confusion: same data with different meaning -or-
           different data with same meaning.

Elements of the Relational Model include:
tables (relations), tuples (rows), & attributes (columns)
keys (primary, combined/concatenated, foriegn)
Normalization