application / x-www-form-urlencoded: This is the default request form the form mode, will be encoded into a unified form data string sent to the server in the form of key-value pairs. And this we re-coded string of html file has been set up.
enctype = "multipart / form-data": This is mainly used for the transport stream, the form will not be provided to form the flow, but according to their original format, file using the file stream, using a string type.