Bokeh (derived from Japanese, a noun boke 暈け, meaning "blurred or fuzzy") 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. Different lens bokeh produces different aesthetic qualities in out-of-focus backgrounds, which are often used to reduce distractions and emphasize the primary subject.
Mike Johnston, former editor of Photo Techniques magazine, claims to have coined the bokeh spelling to suggest the correct pronunciation to English speakers, replacing the previous spelling boke that derived directly from the Japanese word for "fuzzy" and had been in use at least since 1996. It can be pronounced /ˈboʊke/ or /ˈboʊkə/ (boke-aay or boke-uh).
The term bokeh has appeared in photography books at least since 2000.
For more detailed information visit Wikipedia