I want to know what creates an URL of a site for example a view,panel etc. Which command should I write on the Devel module on "Execute php" ? Thanks
Not really sure what you are meaning by 'create url', but any url in Drupal is registered through hook_menu(). Don't let the name confuse you - this is a seperate concept to lists of urls (like the navigation menu). The menu system keeps a cache of url to callback function mappings, which you can inspect to see which function each url points to.
To view the menu cache, you can run this code:
You can then look through the array to see the details for each url.