No, wait. I literally lost the count on how many layers of abstraction there are now for package management.
I feel sorry for you, then... you can't count to one. Because of all the package management elements in use, PackageKit is the only abstraction layer, designed to hide the split between Debian and Redhat packaging.
The rest of the layers (and really, there aren't that many of those either) are providing real functionality, not just abstraction. Here's the list:
RPM, for the basic packaging (equivalent to DEB/dpkg on Debian systems).
YUM (or it's DNF successor, of which Hawkey is part), which provides the ability to install packages and dependencies from repositories (equivalent to apt-get on Debian)
PackageKit, which provides an API that apps like media players can use to help the user install missing codecs, without those apps needing to worry about the differences between Redhat and Debian package management.
Various GUI frontends for the above, to allow users to install apps without having to use command-line tools