When you are trying to install a file via RPM, you
might have several dependent packages that you will have to download
and install first.
APT (Advanced Package Tool) can help with the issues of
dependencies.
APT will try to download and install any dependent
packages needed.
APT will look into all the RPM repositories that you
have listed for the packages and dependencies.
If your repository does not contain your package or
all the needed dependencies, then you can either add more repositories,
or you can download the missing RPM files and install those yourself.
APT will download a package, any needed dependencies,
and will use RPM to install the packages.
This means APT will keep up the RPM database.
APT originally started as part of the Debian
distribution, but is so useful, it has since been ported to many other
RPM based distributions.