What is "relational-model"

Questions that refer the relationship between data and tables should contain this tag.

The relational model is based on two concepts: concept of entity and relation - An entity is an element characterized by the data that are collected in its identification commonly called table. In the construction of the table the data of the entity is identified. The attribution of values to an entity builds a record of the table. The relationship determines how each record in each table is associated with records in other tables.Wikipedia