Bokeh

"Bokeh (derived from Japanese, a noun boke 暈け, meaning "blur" or "haze") is a photographic term referring to the appearance of point of light sources in an out-of-focus area of an image produced by a camera lens using a shallow depth of field. backgrounds, which are often used to reduce distractions and emphasize the primary subject. Different lens bokeh produces different aesthetic qualities in out-of-focus" Wikipedia