A relational database is a database that conforms to the relational model, and refers to a database's data and schema (the database's structure of how that data is arranged).

Common usage of the term "Relational Database Management System" (RDBMS) technically refers to the software used to create a relational database, but sometimes mistakenly refers to a relational database.

• http://en.wikipedia.org/wiki/Relational_model
• A relational database is a database that conforms to the relational model, and refers to a database's data and schema (the database's structure of how that data is arranged).
  
  Common usage of the term "Relational Database Management System" (RDBMS) technically refers to the software used to create a relational database, but sometimes mistakenly refers to a relational database.
• http://en.wikipedia.org/wiki/Relational_database