mage.exe

Manifest Generating and Editing Tool (MAGE)
Both the files can be edited using the Manifest Generating and Editing Tool
Can be used to change the Publish location and re-sign the manifest.
This tool ships with Visual Studio and provides a graphical interface for editing deployment manifests

You can access the ClickOnce deployment from (Project > Properties)(Publish tab).
The Publish version number if made up of four numbers:
Major.Minor.Revision.Build
The publish number represents the overall version of your solution based on all the individual files.
The Build number is automatically incremented every time your publish your solution.

C :\ Program Files\Microsoft SDKs\Windows\ v6.0A\bin\mage.exe
This clears the application cache

dfsvc.exe - is the actual "ClickOnce" engine that is handling the update checks & downloads.
It is launched when a "ClickOnce" application needs updated. It shuts itself down if not used for 15 minutes.