What is an RPM???

The RPM Package Manager (RPM) is a powerful command line driven package management system capable of installing, uninstalling, verifying, querying, and updating computer software packages. Basically, it is software!

Where can I go to get them???

This is a great site to get RPM's

How do I add them and remove them???

If you are saving from the internet, then you choose the RPM you want, right click and save to your hard drive. Your system should recognize and install for you. Here is another site that may answer more of your questions.

How do they compare with other software???

The biggest difference is that RPM's are free!!! However, in your quest for the perfect RPM, don't get into a hurry. To find good stuff you have to search and that can take some time.