instaed of having mechanical bellcranks on the heli connected to the swash plate and servos your servos connect directly to the swash and are mixed electronically in the transmitter. now most all todays transmitters offer this feature.

advantages: less parts, lighter weight heli. (caliber30 come standard with both systems) slop free controls (crisp precise)

disadvantages: as a beginner have cumputer mixing skills, servos need to be higher quality/expense digital servos usually with high speed response times. servos under higher stress workloads. Rx battery drain a lil more noticable.