"Follow Up" Steering
This is the normal method of steering and involves the feedback of steering angle to the helm. This is suited to both manual and automatic operation.
The ships heading may be set into the autopilot which can then compare the actual to desired heading and adjust the rudder angle to suit
"Non-follow Up" Steering
Normally used for back up purposes only. Consists of a single lever per steering gear unit, by moving the lever in on direction the rudder will begin to turn, the rudder will continue to turn until the lever is released or it reaches the limit of its operation