The system that manages this structure are called Relational databases (or RDMS) .
They are founded on Set Theory and are based on the Relational Model, which is a set of principles for relational databases formalized by Dr. E.F. Codd (an IBM Engineer). The concept was introduced in the late 1960s through a paper titled A Relational Model of Data for Large Shared Banks. In the relational model of a database, all data is represented in terms of tuples (row), grouped into relations (table).
All operations on a table return a table. The operation can then be chained together. Relational algebra expressions dictate how to achieve an answer by giving what operations to do and in what order to do them.
SQL is the standard language used to operate on table and its auxiliary data Structure (such as view, aggregate,…) within relational databases.