What is the role of SQL and in what scenarios is it used?

SQL (Structured Query Language) is a query language for working with relational databases.

Role of SQL:

• Allows creating, modifying, and deleting data structures (tables, indexes).
• Performs selection, insertion, updating, and deletion operations.
• Manages access rights and transactions.

Use cases:

• Web applications for storing and retrieving user data.
• Analytics and reporting, where data needs to be aggregated and filtered.
• Inventory management systems, accounting, CRM, and other business applications.

Example of a simple selection query:

SELECT name, email FROM users WHERE active = 1;

In Node.js, SQL is often used through libraries (e.g., mysql, pg) to interact with databases from server-side code.