ES1404-24V is a 5 10/100Mbps ports unmanaged switch that requires no configuration and provides 4 PoE (Power over Ethernet) ports. It can automatically detect and supply power with all 24V passive PoE compliant Powered Devices (PDs).
In this situation, the electrical power is transmitted along with data in one single cable allowing you to expand your network to where there are no power lines or outlets, where you wish to fix devices such as APs, IP Cameras or IP Phones, etc.