SQL- Structured Query Language-  structural language of qestions used to creating and modify the bases of data as well as to placing and download from bases of data the data.
Language SQL is declarative language. It the decision about way of storage and the system of management was left was the delivery fee of data the base of data. It is the language of questions worked out in years seventieth in firm IBM. He bechance the standard in communication from servers the relational of bases of data.
Many at present of systems the relational of bases of data uses to communication with user the SQL, so it is think that using from relational of bases of data- this using from SQL. First firm which SQL included to her commercial product was Oracle. Introducting SQL in products diffrent firms it joined from introducting the modification of primitive language inseparably, soon maintenance unitformity of language requird introduction of standard.