Difference between SQL and DBMS SQL?

What is the difference between SQL and DBMS SQL? And also tell that why its nessesary to install and whats for it is used?

SQL so called Structured Query Language is a database language used to insert, delete or update records in the database. For example, you have stored an employee's city as "Lahore" after two years the employee shifted to Islamabad, Now you have to change the city. For this purpose you will use SQL which you will learn in details later in this course. Both SQL and DBMS SQL are same.

You have to learn to install a DBMS called SQL Server to practice SQL