Defined in 1992 by the Internet Engineering Task Force (IETF), multipurpose internet mail extensions, or MIME types, are a specification for formatting non-ASCII messages so that they can be sent over the internet.
When a browser comes across a file in an HTML document with a MIME extension (like .gif), the browser knows to display that file as an image. Many email clients also support MIME, enabling them to send and receive embedded media via the internet mail system.
