An absolute path or full path is a unique location of a file or directory name within a computer or filesystem, and usually starts with the root directory or drive letter. Directories and subdirectories listed in a path are usually separated by a slash (/).

Example: /Users/Matt/www/blog/images/icecream.jpg

To find the absolute filesystem path of the directory containing a web page, copy the code below into a new text file, save the file as path.php (thus making a simple PHP web page), and move that file to your web server. Then direct your web browser to the URL address of that file (e.g. http://www.example.com/path.php).

 
    

 

Reference http://codex.wordpress.org/Glossary