The Common Gateway Interface (CGI) is a protocol with an Request and Response information on server,

i will give some environment variables passed into CGI script

SERVER_NAME

The server return name of Host and IP address

SERVER_SOFTWARE

Its return server name and version information

SERVER_PORT

Its return port number for request sent system information

SERVER_PROTOCOL

its return name and version of software using client machinre

REQUEST_METHOD

The methods of requrest Divided into two part GET and POST

The Get method Get URl string values from server,its visible to end user,and post method is used to post information to server its not visible content

PATH_INFO

its returns path information on CGI Script

QUERY_STRING

its used to get URL String information from cgi script

REMOTE_USER

its return an login user name from REMOTE_ADDR

REMOTE_ADDR

its get hosting ip address of remote Host

REMOTE_HOST

The host name of client machine

CONTENT_TYPE

Its MIME Content information on Client machine

CONTENT_LENGTH

its return content legth received from host

HTTP_ACCEPT

its retrun What are accepted request from client machine

HTTP_USER_AGENT

its used to findout feature information

CONTENT_ENCODING

its a encoding method,encode user information

CONTENT_LANGUAGE

Its having ISO 3316language code and ISO 639 Country Code