Chapter 2. Introduction to RHN Channels
A Red Hat Network channel is a collection of software packages. Channels help you segregate packages by sensible rules: a channel may contain packages from a specific Red Hat distribution, for instance. A channel may contain packages for an application or family of applications. Users may also define channels for their own particular needs; a company may create a channel that contains packages for all of the organization's laptops, for example.
2.1. Base Channels and Child Channels
There are two types of channels: base channels and child channels. A base channel consists of packages based on a specific architecture and Red Hat Enterprise Linux release. A child channel is a channel associated with a base channel that contains extra packages.
A system must be subscribed to only one base channel. A system can be subscribed to multiple child channels of its base channel. A subscribed system can only install or update packages available through its Red Hat Network channels.
When a system is registered with Red Hat Network, it is assigned to the base channel that corresponds to the system's version of Red Hat Enterprise Linux. Once a system is registered, its default base channel may be changed to a private base channel on a per-system basis via the RHN website. Alternately, you can have activation keys associated with a custom channel so that systems registering with those keys are automatically associated with the custom channel.
On the Red Hat Network website, the Channels page (located under the Channels tab on the top navigation bar) provides a list of all base channels and their child channels. Clicking on the name of a channel displays the Channel Details page, which provides a list of all of the packages in that channel, its errata, and any associated systems.