What is a "Flight Director"?
The flight director is related to the autopilot system. It displays a guide on the artificial horizon, which shows the attitude of the airplane, but does nothing to control the plane. The guide represents a reference of an airplane attitude that will follow the parameters set for the autopilot. The pilot can manually fly the plane directly where the flight director indicates, and by doing so the plane will follow the parameters set for the autopilot.

If the autopilot is engaged, autopilot flies the plane to follow the flight director. The flight director serves as a visual indication of where the autopilot wants the plane to go. Although a flight director typically accompanies an autopilot system, some aircraft have a flight director without an autopilot.

The procedure to engage them is to first turn on the flight director, which will show where the autopilot wants the plane to be, and then to engage the autopilot, which will then automatically fly the plane.

This is what the autopilot controls can look like.



Here is the Boeing flight director, visible as the crossed magenta lines in the center of the screen.