A structured query language (SQL) is a language that is used to operate relational databases. Some of the major ways in which SQL is used in conjunction with a relational database is for the purposes of storing, retrieving, and manipulating data stored in a relational database. Despite being older than other languages, it is still widely used all over the world. That's why SQL training are so popular these days.

Why SQL is so popular?
Structured Query Language or SQL programming is used so extensively for the following reasons.

SQL lets you access any data within the relational database
You can describe the data in the database using SQL
Using SQL you can manipulate the data with the relational database
SQL can embed within other languages through SQL modules & libraries
SQL lets you easily create and drop databases and tables
SQL allows you to create views, functions and stored procedures in databases
Using SQL you can set permissions on procedures, tables and views.

Why should you learn SQL?

To pursue a very broad career spanning a lot of roles of responsibilities of course. To pursue a very broad career spanning a lot of roles of responsibilities of course. Also, learning SQL helps you if you want to be a data scientist. As, this career also deals with relational databases and queries using the standard language SQL.