$_SERVER คือ ตัวแปร PHP ชนิดพิเศษที่ทำหน้าที่ต่าง ๆ เกี่ยวกับข้อมูลของเครื่อง Server ที่ใช้ Run Script PHP

<?php
echo "\$_SERVER[\"HTTP_ACCEPT\"] = ".$_SERVER["HTTP_ACCEPT"]." ";
echo "\$_SERVER[\"HTTP_ACCEPT_LANGUAGE\"] = ".$_SERVER["HTTP_ACCEPT_LANGUAGE"]." ";
echo "\$_SERVER[\"HTTP_ACCEPT_ENCODING\"] = ".$_SERVER["HTTP_ACCEPT_ENCODING"]." ";
echo "\$_SERVER[\"HTTP_USER_AGENT\"] = ".$_SERVER["HTTP_USER_AGENT"]." ";
echo "\$_SERVER[\"HTTP_HOST\"] = ".$_SERVER["HTTP_HOST"]." ";
echo "\$_SERVER[\"HTTP_CONNECTION\"] = ".$_SERVER["HTTP_CONNECTION"]." ";
echo "\$_SERVER[\"PATH\"] = ".$_SERVER["PATH"]." ";
echo "\$_SERVER[\"SystemRoot\"] = ".$_SERVER["SystemRoot"]." ";
echo "\$_SERVER[\"COMSPEC\"] = ".$_SERVER["COMSPEC"]." ";
echo "\$_SERVER[\"PATHEXT\"] = ".$_SERVER["PATHEXT"]." ";
echo "\$_SERVER[\"WINDIR\"] = ".$_SERVER["WINDIR"]." ";
echo "\$_SERVER[\"SERVER_SIGNATURE\"] = ".$_SERVER["SERVER_SIGNATURE"]." ";
echo "\$_SERVER[\"SERVER_SOFTWARE\"] = ".$_SERVER["SERVER_SOFTWARE"]." ";
echo "\$_SERVER[\"SERVER_NAME\"] = ".$_SERVER["SERVER_NAME"]." ";
echo "\$_SERVER[\"SERVER_ADDR\"] = ".$_SERVER["SERVER_ADDR"]." ";
echo "\$_SERVER[\"SERVER_PORT\"] = ".$_SERVER["SERVER_PORT"]." ";
echo "\$_SERVER[\"REMOTE_ADDR\"] = ".$_SERVER["REMOTE_ADDR"]." ";
echo "\$_SERVER[\"DOCUMENT_ROOT\"] = ".$_SERVER["DOCUMENT_ROOT"]." ";
echo "\$_SERVER[\"SERVER_ADMIN\"] = ".$_SERVER["SERVER_ADMIN"]." ";
echo "\$_SERVER[\"SCRIPT_FILENAME\"] = ".$_SERVER["SCRIPT_FILENAME"]." ";
echo "\$_SERVER[\"REMOTE_PORT\"] = ".$_SERVER["REMOTE_PORT"]." ";
echo "\$_SERVER[\"GATEWAY_INTERFACE\"] = ".$_SERVER["GATEWAY_INTERFACE"]." ";
echo "\$_SERVER[\"SERVER_PROTOCOL\"] = ".$_SERVER["SERVER_PROTOCOL"]." ";
echo "\$_SERVER[\"REQUEST_METHOD\"] = ".$_SERVER["REQUEST_METHOD"]." ";
echo "\$_SERVER[\"QUERY_STRING\"] = ".$_SERVER["QUERY_STRING"]." ";
echo "\$_SERVER[\"REQUEST_URI\"] = ".$_SERVER["REQUEST_URI"]." ";
echo "\$_SERVER[\"SCRIPT_NAME\"] = ".$_SERVER["SCRIPT_NAME"]." ";
echo "\$_SERVER[\"PHP_SELF\"] = ".$_SERVER["PHP_SELF"]." ";
echo "\$_SERVER[\"REQUEST_TIME\"] = ".$_SERVER["REQUEST_TIME"]." ";
echo "\$_SERVER[\"argv\"] = ".$_SERVER["argv"]." ";
echo "\$_SERVER[\"argc\"] = ".$_SERVER["argc"]." ";
?>