A relational database is a single data repository that provides both structural and data independence while maintaining conceptual simplicity.
The relational database model is perceived by the user to be a collection of tables in which data are stored. Each table resembles a matrix composed of row and columns. Tables are related to each other by sharing a common value in one of their columns.
The relational model represents a breakthrough for users and designers because it lets them operate in a simpler conceptual environment. End users find it easier to visualize their data as a collection of data organized as a matrix. Designers find it easier to deal with conceptual data representation, freeing them from the complexities associated with physical data representation.