RPM is RedHat's Package Manager. More software is distributed via RPM than any other format (i.e. more than the apt format). Actually, no. Probably tar.gz is the most common. I digress.
A couple of handy tips...
Install an RPM:
rpm -Uvfh anrpmfile.rpm
An http URL (e.g. "http://aserver.com/anrmpfile.rpm") will work just as well as a file name. FTP works also.
To find out what files are in an RPM (and what scripts are run when you you install it - e.g. what users are set up):
rpm -qp --list --scripts --configfiles anrpmfile.rpm
-q is query, -p means from a rpm file.
rpm -qp --filesbypkg anrpmfile.rpm
To find out what is installed on your server:
rpm -qa # | grep thepackagenameyoureinterestedin
To find out which RPM installed a particular file on your server, run:
rpm -q --whatprovides /lib/ld-2.3.2.so and it will report
something like 'glibc-2.3.2-95.30'.