suPHP is a tool for executing PHP scripts with the permissions of their owners.
suPHP is a tool for executing PHP scripts with the permissions of their owners. In practice this means that a user can execute a script within his own files and folders. It consists of an Apache module (mod_suphp) and a setuid root binary (suphp) that is called by the Apache module to change the uid of the process executing the PHP interpreter.
It is often used on systems where there are multiple clients present.