Businesses and organizations archive old Web pages or Web forums for various reasons. Typically, attempting to save an entire Web page involves keeping track of a large folder of files. Sometimes, achieving a perfect replica of a Web page may not seem possible because it uses resources located on other Web pages. The primary difference between HTML and MHTML, a newer protocol, is that it allows you to download a Web page using the basic principles of Internet email.
Short for Hyper Text Markup Language, HTML documents contain a series of tags and commands that govern how a Web browser displays pages on the Internet. In regard to email, plain HTML allows for various tags that include hyperlinks within the body of an email and text attachments. However, plain HTML email cannot transmit non-text attachments or media. As such, it is very limited and it became necessary to upgrade its capabilities.
The answer for HTML email's shortcomings arrived in the form of MIME. Short for Multipurpose Internet Mail Extensions, the development of MIME changed the face of email. With the MIME protocol, Internet mail could now include images, contain multi-part message bodies and even nonstandard characters within email headers. MIME defines formatting for non-text messages and allows for the transmission of other media, such as music or video, within emails. Most email as of the time of publication utilizes the MIME format.
Short for MIME HTML, MHTML uses the MIME email protocol to combine items into a single Web page archive file. In the same way that MIME allows for transmission of media-rich emails, MHTML also creates its own "email" in the form of an archived Web page. This means MHTML allows developers to gather an underlying HTML document, along with its embedded images and media, into a single file. This archive can also include linked documents, if the developer wishes, by use of Content-ID URLs embedded with the MHTML document's header.
HMTL and MHTML, while closely linked, have major differences. Any MHTML document utilizes an underlying HTML Web page, but only MHTML can package an entire Web page into a single file when downloaded. In contrast, when saving an HTML document, a computer creates a folder that includes multiple files that were embedded within the original HTML document. These loose files, if accidentally deleted or lost, can make viewing a saved Web page impossible. With MHTML, since all files gather into one archived format, the archival of online Web pages becomes much easier and less cluttered.