If you have the latest Mac and the latest iPhone or iPad running Apple's latest OSes, and if you have Wi-Fi and Bluetooth turned on, the new Continuity features work like magic. What powers that magic? A wide range of network options, including Bluetooth Low Energy (BTLE), peer-to-peer Wi-Fi, regular local networking, and iCloud/iMessage. Each aspect of Continuity actually picks and chooses from these connectivity options, sometimes using more than one.
Let's take a look at the various network requirements behind each feature. - Ars Technica
Reminds me once again that just like iCloud, Continuity is only a marketing name for what is basically dozens of separate technologies that, in theory, just work.