The term bokeh gets bandied about with some degree of abandon these days, as fashionable or trendy words tend to be. And it's not just popular among the Instagram hipsters. Serious photographers and beginner shooters alike seem to be bonkers for bokeh.
A few of you might have heard the term but may still not know exactly what bokeh is. Bokeh is derived from a Japanese word meaning “blurred” or “hazy,” and it's used to describe the character of the out-of-focus areas of a photographic image. There is good and bad bokeh, and…
via Imaging Resource News Page http://www.imaging-resource.com/news/2013/09/11/understanding-bokeh-the-art-and-science-behind-the-beauty-of-blur-part-1