Gaussian blur is a digital image processing technique used to create a smooth, softening effect on images. It works by averaging the pixels around a target pixel, weighted by a Gaussian function, which gives more importance to nearby pixels. This results in a blurred image that reduces noise and detail, making it useful for various applications like background softening or creating a dreamy effect. The technique is named after the mathematician Carl Friedrich Gauss, whose bell-shaped curve describes the distribution of weights. Gaussian blur is commonly used in photo editing software and graphic design to enhance images or focus attention on specific areas.