It's a bit astonishing but looks like some people confuse URL and PATH.

URL - is something like http://domain.com/blabla/, ie a place on the internet

PATH - is a position of a file on a disk

For example

Usually domain's folder at your server has a path like /home/user/domain.com/. Let's say there's a file named 1.html. It would have a PATH /home/user/domain.com/1.html and URL - http://domain.com/1.html

Периодически возникают вопросы по относительным и абсолютным путям. Относительный путь - это путь относительно текущего положения в системе, оно может менятся. Путь вида /home/user/domain.com/1.html (тут / в начале пути указывает на корень файловой системы) - это абсолютный путь, он не меняется.

That's why we have 2 settings to save thumbs.

• PATH where we are going to store files , for example /home/user/domain.com/thumbs/
• and URL like http://domain.com/thumbs to get real URL thumb which is sometimes impossible to get from PATH (yes, URL is pretty obvious in this example, but it's not always this way.