The Structured Query Language is used in manipulating data stored in Relational Database Management Systems (RDBMS).
SQL provides commands through which data can be extracted, sorted, updated, deleted and inserted.
SQL has the full support of ANSI (American National Standards Institute), which has laid down certain rules for the language.
SQL can be used with any RDBMS such as MySQL, mSQL, PostgresSQL, Oracle, Microsoft SQL Server, Access, Sybase, Ingres etc.
All the important and common SQL statements are supported by these RDBMS, however, each has its own set of proprietary statements and extensions.