When a web server sends a document, it does not just send the contents of the document. Additional information is sent to tell the Browser what sort of file this is. A mime type is something usually of the form 'text/html'. That would tell the browser that this is a text file of the type HTML. MyWebServer associates mime types by file extension. The mime configuration allows you to add or remove mime conversions. Mime conversions for common file types have been included for your convince. This allows files with file extensions you associate to mime types to be be recognized by the users web browser as that mime type when it is received. 

When you first enter the mime configuration screen, you will be shown a list of all the mime conversions currently in place. You also have two forms, one for addition/modification and another to delete mime conversions.