Active Shutter is a 3D technology used in some Smart TVs and glasses.
The TV shows two images very quickly—one for the left eye and one for the right eye. The active shutter glasses open and close in sync with the TV, so each eye only sees its correct image.
This creates a 3D effect with full resolution for each eye, unlike passive 3D glasses that split the resolution. For example, when watching a 3D movie, you see sharper and more detailed images with active shutter glasses.
See also: 3D TV, Passive 3D, Refresh Rate