SQL use the term query as the name for its commands. Basically, all SQL code is written in the form of a query statement and then executed against a database.
RDBMS stands for Relational Database Management System. RDBMS is the basis for SQL, and for all modern database systems like MS SQL Server, IBM DB2, Oracle, MySQL, and Microsoft Access. A Relational database management system (RDBMS) is a database management system (DBMS) that is based on the relational model as introduced by E. F. Codd.
SQL plays an important role in data analysis. When we are analyzing more number of records, we summarize the data and then analyse it. We do lot of ETL tasks to extract the data from data base and clean and format the data. Once we are created a clean data set, we go for analyzing the data to get more insights from the data.