A router is a network device allows communication between the internet and your connected devices.
A POE Adapter is a power supply and used in large units, free standing houses or when a booster is used.
The ONU connects the termination box to the router. The router itself does not have a fibre port, hence the need for an ONU.
The termination box is installed by the Civils Team. It allows the Fibre underground to run into the house. The ONU is then connected to the Termination box using patch leads.
POWER ADAPTER/SWITCHING ADAPTER
The power adapter is only used with the ISP routers that do not have a POE Adapter.