A relational database is a type of database that stores and provides access to data points that are related to one another. It is based on the relational model of data, as proposed by E. F. Codd in 1970. In a relational database, data is organized into rows and columns, which collectively form a table. Tables are used to hold information about the objects to be represented in the database, and each column in a table holds a certain kind of data. The rows in the table represent a collection of related values of one object or entity. Each row in a table could be marked with a unique identifier called a primary key, and rows among multiple tables can be made related using foreign keys.
The relational data model provided a standard way of representing and querying data that could be used by any application. From the beginning, developers recognized that the chief strength of the relational database model was in its use of tables, which were an intuitive, efficient, and flexible way to store and access structured information. The simple yet powerful relational model is used by organizations of all types and sizes for a broad variety of information needs. Relational databases are used to track inventories, process e-commerce transactions, manage huge amounts of mission-critical customer information, and much more.
Relational databases use a set of constraints to enforce data integrity in the database, including primary keys and foreign keys. SQL is used to add, update or delete rows of data, retrieving subsets of data for transaction processing and analytics applications, and to manage all aspects of the database.
