Why is Wi-Fi called en0, like ethernet, on a Mac OS X?
Linux has been my main system for years now. In Linux, ethernet hardware devices have names like eth0 or enp1s0 (the latter I've only seen on Arch Linux). The wireless card has always had names like wlan0 or wlp2s0 (again the latter on Arch). On my new MacBook Air, the wireless network is assigned en0, which I've read stands for ethernet. Also, there's an en1 even though I don't have an ethernet port. What does this naming convention mean?
Answer
It's worth keeping in mind that OSX is not Linux, it is basically BSD. And in BSD network interfaces are named after the device driver that manages the interface, not necessarily based on the type of device. My guess is that the same driver supports both built-in WiFi interfaces and wired NICs on Apple computers.
You can list all interfaces using the command
networksetup -listallhardwareports
On my Macbook this lists a number of interfaces (WiFi, Bluetooth, Thunderbolt) and they are all named enX.