Move storage directory outside webmap

Ok, so i have my opencart in dutch so i will try to explain it as good as i can.
After my installing of opencart on my main server pad, i get this security notice about moving my storage directory outside my webmap.
Can anyone tell me why i have to do this?

Can anyone tell me why i have to do this?

There are enough posts on the forum that demonstrates how to do this. While the OC version has not been posted, you simply need to move your system/storage folder outside your public_html folder by also ensuring your folder permissions are recursively set to 0755. Then, to edit your config.php and admin/config.php files to set your new DIR_STORAGE path for your new location of the storage folder.

Lastly, to comment out or remove the entire line in your .htaccess file where it says: ^system/storage folder. Clear your OC cache from your admin - > dashboard - > blue square icon and from your admin - > extensions - > modifications - > refresh button.