Why do I need to use Class.forName("org.postgresql.Driver") and why my code works without it?

Question

1. Why I need to use Class.forName("org.postgresql.Driver"); and what is it stands for?
2. Why my code work without it despite everywhere says that it wouldn't work without it? (I used it in empty project so Class.forName("org.postgresql.Driver") has not been executed there)

import java.sql.*;

public class Solution
{
    public static void main(String[] args)
    {
        final String DATABASE_URL = "jdbc:postgresql://localhost:5432/postgres";
        final String USER = "postgres";
        final String PASSWORD = "123";

        try
        {
            Class.forName("org.postgresql.Driver");
        }
        catch (ClassNotFoundException e)
        {
            e.printStackTrace();
        }

        String sqlQuery = "SELECT * FROM students;";
        try (Connection connection = DriverManager.getConnection(DATABASE_URL, USER, PASSWORD);
             Statement statement = connection.createStatement();
             ResultSet resultSet = statement.executeQuery(sqlQuery);
        )
        {
            System.out.println("Connected successfully");
            while (resultSet.next())
            {
                String name = resultSet.getString("name");
                int age = resultSet.getInt("age");
                System.out.printf("name: %s, age: %d\n", name, age);
            }
        }
        catch (SQLException e)
        {
            e.printStackTrace();
        }
    }
}