Using LAN cabling is the ideal solution for hooking up devices to your routers and access points. When this simply isn't possible, Synology makes it so you can use a Wi-Fi dongle with the DS119j NAS.
I've always been a big proponent of using NAS (Network Attached Storage) devices for dedicated file and media storage and backup. They are a low-power, low-cost alternative to a dedicated PC server, ...