What is Microsoft Internet Explorer?

Viewer Programs/Helper Applications

To help a user view or hear certain file types, helper applications, referred to as "viewers" by Internet Explorer, can be launched from within Internet Explorer. Viewers are software applications that are used to display images, open files, hear sounds, view movie clips, etc.

For example, Internet Explorer can be configured so that a particular audio player software package is automatically invoked when a user clicks on a link to an audio clip.