Ambari Server uses Version Definition Files (VDF) to understand which product and component versions are included in a release. The VDF file contains various Operating System and their Repo URLs. VDFs also provides individual components name & version information that are shipped with that verison of product.
Users can also create their own VDFs (by following the same format as mentioned in the above VDF) by editing the <repoid/> tags informations for each repository to match their Local repository OR Satellite/Spacewalk channel names previously configured.