A type of database that defines multiple and complex relations among different data using tables (rows and columns of data). In a relational database, the rows of a table represent records (collections of information about separate items) and columns represent data items (particular attributes of a record). Relationships among data items are not physically stored. Instead, data is stored in tables, and relationships between two or more records are established by matching the values of columns common to those tables. See also relational database management system.