What are MIME Types?
MIME (Multipurpose Internet Mail Extensions) types tell browsers how to handle specific extensions. MIME types are often used to handle new technologies as they appear. When WAP technology first appeared, no one had these extensions set up on their server. However, with MIME types, users could have set it up themselves and could have begun serving WAP pages immediately.
For example, the text/html MIME type equates to .htm, .html and .shtml extensions on most servers; and this tells your browser to interpret all files with those extensions as HTML files.
MIME Types in cPanel
You can add and alter new MIME types specifically for your site. Here is an example of the cPanel interface:
In the example above, Apache is being told to to treat .html and .htm files as PHP files. This is helpful if your .html files have PHP code inside but you cannot rename the files to the .php extension; however, this is notably more resource intensive and should be used with caution.
MIME Types in Plesk
Please see the Plesk User Guide article on Adding/Removing MIME types in Plesk.