php man page for _files

_FILES(3)								 1								 _FILES(3)

$_FILES - HTTP File Upload variables

	An associative array of items uploaded to the current script via the HTTP POST method.

       $HTTP_POST_FILES  contains  the	same  initial information, but is not a superglobal. (Note that $HTTP_POST_FILES and $_FILES are different
       variables and that PHP handles them as such)

       +--------+---------------------------------------------------+
       |Version |						    |
       |	|						    |
       |	|		     Description		    |
       |	|						    |
       +--------+---------------------------------------------------+
       | 4.1.0	|						    |
       |	|						    |
       |	|  Introduced	  $_FILES      that	 deprecated |
       |	| $HTTP_POST_FILES.				    |
       |	|						    |
       +--------+---------------------------------------------------+
       Note

	      This  is	a  'superglobal', or automatic global, variable. This simply means that it is available in all scopes throughout a script.
	      There is no need to do global $variable; to access it within functions or methods.

       move_uploaded_file(3), Handling File Uploads.

PHP Documentation Group 														 _FILES(3)