What does 3d sync out mean?

3D sync out refers to a feature found in some 3D displays or projectors that allows for the synchronization of 3D content between the display and external devices, such as 3D glasses or other equipment. This synchronization ensures that the left and right images are displayed at the correct times, creating a cohesive 3D viewing experience. It often involves sending a signal to activate the shutter glasses at the appropriate moments, enhancing the overall quality of the 3D effect.