in laravel, artisan is a file under root/protected page
for example,
c:\xampp\htdocs\my_project\protected\artisan
you can view the content of "artisan" file with any text editor, it's a php command syntax
so when we type
php artisan
we tell php to run php script in "artisan" file
for example:
php artisan change
will show the change of current laravel version
to see the other option, just type
php artisan