Mysql and php artisan

Hi, I just wondering what makes php artisan (or the project itself) asking to have MySql runnig while I run, in example, php artisan in a command line ,just to see the commands, and I get this error [PDOException] SQLSTATE[HY000] [2002] No connection could be made because the target machine actively refused it., but if I turn on the MySql it works. I have a project on Laravel 5.2