PHP Input Vars is a PHP security measure designed to limit the number of "post variables" you can use to execute a function. It defines the number of variables your server can use when running a function.
This sets the maximum time in seconds a script is allowed to parse input data, like "POST and GET". Timing begins at the moment PHP is invoked at the server and ends when execution begins. The default setting is -1, which means that max_execution_time is used instead. Set to 0 to allow unlimited time.
If the max_execution_time exceeds, then there is an explicit error message that the max_execution_time has been exceeded.