SQL stands for Structured Query Language. It is a standard query language used to work with the Relational Database Management System. You can write SQL statements to execute queries against a database; you can write statements to perform tasks like insert data into a database, update data on a database, retrieve or delete data from a database.
Some relational database management systems working with SQL are – Microsoft SQL Server, PostgreSQL, MariaDB, Access etc.
SQL is a standard of the American National Standards Institute (ANSI). The above-mentioned DB management systems modify SQL to add additional properties and statements to work with that particular RDBMS. However, they all support standard SQL commands such as SELECT, UPDATE, DELETE, INSERT, WHERE, etc.