2 Chapter 1. What is Red Hat Network?probing the software packages installed on your system to create a Package Profile. This informationis sent to RHN, and RHN returns a unique System ID to your system. See Chapter 6 Red Hat NetworkRegistration Client for more information.Many Red Hat Network terms are used throughout this manual. As you read the Red Hat NetworkManagement Reference Guide, refer to the Glossary as necessary for an explanation of common terms.TipFor a comparison chart of RHN service levels, refer to https://rhn.redhat.com/preview/.1.1. DemoThe RHN Demo service level is the complimentary service level. All users receive one free subscrip-tion to RHN Demo. All that is required is the completion of a brief survey once every 60 days.With each Demo subscription, you receive:• Errata Notifications — Be the first to know about Red Hat’s patches. Subscribe to email erratanotification through Red Hat Network.• Errata Updates — Immediately bring individual systems up-to-date with the click of a button.• Search Packages — Search through the full repository of RPMs available to Red Hat Networkusers.• Search Errata — Search through the collection of all errata ever released through Red Hat Network.1.2. UpdateThe RHN Update service is ideal for a user with one Red Hat Linux system or a small numberof Red Hat Linux systems to keep updated. Subscription to Update can be purchased athttp://rhn.redhat.com/purchase_info.pxt.With each Update subscription, you receive the essential functionality provided to Demo users, plus:• Easy ISOs — For customers who have purchased subscriptions to Red Hat Network, ISO imagesare available for immediate download. Beat the rush to the FTP servers by downloading directlyfrom Red Hat Network.• Priority Access during periods of high load — When Red Hat releases a large errata, users withPriority Access can be guaranteed that they will be able to access the updated packages immediately.• RHN Support Access — All paying customers of Red Hat Network receive web based support fortheir RHN questions.• Errata Notification, Multiple Systems — Subscriptions for multiple systems means errata notifica-tion for errata to all of those systems.• Errata Updates, Multiple Systems — Get quick updates for multiple systems with an easy buttonclick for each system.