POE combines both power and data over a single ethernet cable. We use POE technology to connect the DS Hub to cameras that the DS Hub then monitors. At the heart of POE is the POE switch--it powers the cameras and facilitates all of the communication between. You can learn more about POE here: https://en.wikipedia.org/wiki/Power_over_Ethernet
The majority of PoE Switches are compatible with the Deep Sentinel POE system. In a majority of situations an unmanaged switch is sufficient (i.e., the switch does not have a console for setting things like QOS, or viewing traffic or managing devices.). For installs which are 24/7 mission critical, situations with complex network settings, or where corporate IT rules require specific vendors, a managed switch will be the right answer; though these tend to be more expensive.
DS also offers an unmanaged 16-port switch from TP-Link which we support in 90%+ of our installations.
16x PoE+ Ports
Total 250 Watt Power Budget
Available PoE transmission for surveillance up to 273yds