A hub is what connects Spectrio Engage. This is the piece of hardware that runs your digital signage and plays your shows on screen.
A channel is what allows content or project to be scheduled and directed to a particular display or kiosk. Each channel is tied to a single license. Content can be scheduled to one or more channels.
Each channel has to be attached to a hub in order to play content on a screen, but a hub may have more than one channel assigned to it—for example, you could have a hub (computer) at your main office that powers both customer-facing advertisements on one screen and internal announcements for employees on another screen, thus 1 PC with 2 screens equals 1 hub with 2 channels.