Structured Query Language or SQL is a database computer language designed for the retrieval and management of data in relational database management systems (RDBMS), database schema creation and modification, and database object access control management. Although programmers can use it in the same way as other languages, it is often used, as a means for programs to communicate with each other SQL is a standard interactive and programming language for querying and modifying data and managing databases. Although SQL is both an ANSI and an ISO standard, many database products support SQL with proprietary extensions to the standard language.

The core of SQL is formed by a command language that allows the retrieval, insertion, updating, and deletion of data, and performing management and administrative functions. In a procedural language we tell the computer each step to perform. The computer performs those steps and, if they are well written, we will end up with our desired result. SQL is not a procedural language but a declarative language. You write a single SQL declaration and hand it to the DBMS. The DBMS then executes internal code, which is hidden from us. The DBMS returns a set, which is a group of data that is somehow defined. In a declarative language, we carefully phrase what we want and then let the DBMS get it for us. If we have written a good SQL statement then the resulting set of data will be correct.