SQL stands for structured query language. It is designed for
managing data in a relational database management system (RDBMS).
SQL is a database language, it is used for database creation,
deletion, fetching rows and modifying rows etc.
SQL depends on relational algebra and tuple relational calculus. You must also know that all DBMS like MySQL, Oracle, MS Access, Sybase, Informix, Postgres and SQL Server use SQL as standard database language.