$argv is an array of arguments passed to script in PHP, so you can know the parameters when user run the scriptFollowings are the example content of $argv

array(4) {
  [0]=>
  string(10) "script.php"
  [1]=>
  string(4) "arg1"
  [2]=>
  string(4) "arg2"
  [3]=>
  string(4) "arg3"
}