RPM

Main RPM configuration file is /usr/lib/rpm/rpmrc. This file sets a variety of options, mostly related to the CPU optimizations used when compiling source packages. You shouldn’t edit this file, though; instead, you should create and edit /etc/rpmrc (to make global changes) or ~/.rpmrc (to make changes on a per-user basis). The main reason to create such a file is to implement architecture optimizations—for instance, to optimize your code for your CPU model by passing appropriate compiler options when you build a source RPM into a binary RPM.

What package contains file?

rpm -qf /sbin/iptables

Show information about the packege:

rpm -qi package

List all installed packages

rpm -qa

List files in package

rpm -ql package

List configuration files of the package:

rpm -qc package

View changelog of the package:
rpm -q --changelog package

Upgrade or install package:

rpm -U packagename

Upgrade package only if it exists:

rpm -F packagename

Install package older than existing one:

rpm -i --oldpackage

Yum

Update package:

yum update or upgrade package

Check updates:

yum check-update

Remove package with yum:

yum remove or erase package

Information about package:

yum list package