What is "iBridge" interface on new MacBook Pro (later 2016) ?

Today I bought MacBook Pro 13 with Touch Bar, and found an unfamiliar network interface iBridge is configured.

It can be found in "Network Utility, but of course you can see it via ifconfig:

en5: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500 index 4

eflags=1000080<TXSTART,ECN_ENABLE>

ether ac:de:48:00:11:22

inet6 fe80::aede:48ff:fe00:1122%en5 prefixlen 64 scopeid 0x4

nd6 options=281<PERFORMNUD,INSECURE,DAD>

media: autoselect

status: active

type: Ethernet

link quality: 100 (good)

state availability: 0 (true)

scheduler: QFQ

qosmarking enabled: no mode: none

Could you anyone tell me what is this iBridge?