How SQL related to RDBMS

Structured Query Language (SQL) is a standard language for communication with a relational database management system (RDBMS). SQL provides commands which are used to create, modify, and access the database. Databases contain one or more tables of data with relationships between multiple tables defined in the database. Each table is an object.

SQL Commands
Select - Used to retrieve selected data. Example:

select "columnname1", "columnname2" from "tablebasename" [where "condition"];

A "*" may be used to select all columns. The where clause is optional and only one column name must be specified.
Insert
Update
Delete
Create
Drop