The manner in which the display contrast is controlled. Most terminals allow manual control, where the software allows the operator to adjust the contrast while viewing the display. Better terminals also have automatic temperature-based control (temperature compensation), which keeps the contrast from varying as the ambient temperature varies.

A control in a monitor that changes contrasts by increasing or decreasing amplitude of video signal

Is a feature of many video monitors. This allows the user to manually adjust the screen contrast for better picture visibility. Contrast Ratio is a monitor specification. This number indicates the dynamic range of brightness (difference between darkest and brightest) a monitor is capable of displaying.

A manual control for a monitor that affects both luminance and contrast.

is a control in the monitor which changes the contrast by increasing or decreasing the amplitude of the video signal.

A manual gain control for a monitor, affecting both luminance and contrast.