What does RS422 in encoder mean？

RS422 is a signal interface. Line Drive (Line Drive) This circuit power supply voltage is DC5V, TTL level output, and is directly compatible with the international standard RS422 interface. Due to the connection with symmetrical negative signals, the electromagnetic field contribution of the current to the cable is zero. This condition has the least attenuation, the best anti-interference, shorter response time, and longer distance transmission.