Neutral Density filters (ND filters) are optical devices that reduce the intensity of light entering a camera lens without affecting the color of the scene. They come in various strengths, measured in stops, allowing photographers to control exposure and achieve desired effects, such as longer shutter speeds or wider apertures in bright conditions. These filters are particularly useful in landscape photography, where they help create smooth water effects or capture motion in clouds. By limiting light, ND filters enable creative control over depth of field and motion blur, making them essential tools for both amateur and professional photographers.