When the browser sends a request to a web server, it also sends a MIME header.
MIME headers contain name-value pairs, essentially a name followed by a colon and a space, followed by a value.
Connection: Keep-Alive
User-Agent: Mozilla/3.01 (Macintosh; I; PPC)
Host: www.digitalthink.com:80
Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, */*