The relational model is the conceptual basis of relational databases. Proposed by E.F. Codd in 1969, it is a method of structuring data using relations, which are grid-like mathematical structures consisting of columns and rows. Codd proposed the relational model for IBM, but he had no idea how extremely vital and influential his work would become as the basis of relational databases. In the relational model, all data must be stored in relations (tables) and each relation consists of rows and columns. Each relation must have a header and body. The header is simply the list of columns in the relation.