Can you explain what the SQL language is and what it is used for?

SQL (Structured Query Language) is a language for structured queries designed for working with relational databases. It is used for creating, modifying, and managing data in the database, as well as for retrieving information.

Main features of SQL:

• Creating and modifying database structures (tables, indexes, etc.)
• Inserting, updating, and deleting data
• Queries for data retrieval with filtering, sorting, and table joins
• Managing access rights to data

Example of a simple SQL query to select all users over 18 years old:

SELECT * FROM users WHERE age > 18;

SQL is widely used in testing for verifying data correctness, preparing test data, and automating database interactions.