The Encoding Profiles within Mediasite are the base level definition of video quality. Because they define the quality of a single steam of content, more needs to be built around them once they have been created. Out of the box, Mediasite will supply many of the encoding profiles that you will need to use. However, in certain circumstances there may be a need to create an additional encoding profile.
The encoding profiles will come in two different varieties. There are profiles that will be used for smooth streaming with adaptive bitrate. These would be used primarily for live broadcasts. On the other hand, MP4 encoding profiles are used for on-demand content.