The Software Update model defines the information model to let a Software Update Client update the software of different servers.
If such a client deals with devices of various vendors there need to be a standardized file format for the exchange of Software Packages between the creator of the Software Package and the Software Update Client.
This Software Package should have the required meta data like version, compatibility information and supplementary documents like release notes.
There should be an option to deploy just one single file of the package or to deploy the complete software package to the server.