Powerline Networking, where you use the mains electricity cabling to send data throughout your small office, home etc. has always suffered from the ‘one power socket, one data port’ implementation.
The XEPS103, will appeal almost exclusively to people who already own a Netgear router. The router’s power brick takes up one power socket and the powerline adaptor another. The XEPS103 simply melds AC adapter and powerline box into one providing powerline networking and wireless networking both through a single socket.
You don’t have to connect the XEPS103 to a router as it will work just fine as a standalone powerline adapter.