This concept was first described around 1970 by Dr. Edgar F. Codd in an IBM research publication called "System R4 Relational".
A relational database uses the concept of linked two-dimensional tables which comprise of rows and columns. A user can draw relationships between multiple tables and present the output as a table again. A user of a relational database need not understand the representation of data in order to retrieve it. Relational programming is non-procedural.
[What's procedural and non-procedural ?
Programming languages are procedural if they use programming elements such as conditional statements (if-then-else, do-while etc.). SQL has none of these types of statements.]
In 1979, Relational Software released the world's first relational database called Oracle V.2
What a DBMS ?
MySQL and mSQL are database management systems or DBMS. These software packages are used to manipulate a database. All DBMSs use their own implementation of SQL. It may be a subset or a superset of the instructions provided by SQL 92.
MySQL, due to it's simplicity uses a subset of SQL 92 (also known as SQL2).
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