WEB BASIC OVERVIEW
The World Wide Web
MIME (Multi-Purpose Internet Mail Extensions)
MIME is an extension of the original
Internet e-mail protocol that lets people use the protocol to exchange different kinds of data
files on the Internet: audio, video, images, application programs, and other kinds, as well as the
ASCII text handled in the original protocol, the Simple Mail Transport Protocol (SMTP). In
1991, Nathan Borenstein of Bellcore proposed to the IETF that SMTP be extended so that
Internet (but mainly Web) clients and servers could recognize and handle other kinds of data
than ASCII text. As a result, new file types were added to "mail" as a supported Internet
Protocol file type. Servers insert the MIME header at the beginning of any Web transmission.
Clients use this header to select an appropriate "player" application for the type of data the
header indicates. Some of these players are built into the Web client or browser (for example,
all browsers come with GIF and JPEG image players as well as the ability to handle HTML
files); other players may need to bedownloaded. New MIME data types are registered with the
Internet Assigned Numbers Authority (IANA). MIME is specified in detail in Internet Request
for Comments 1521 and 1522, which amend the original mail protocol specification, RFC 821
(the Simple Mail Transport Protocol) and the ASCII messaging header, RFC 822.