In photography, bokeh is the blur or the aesthetic quality of the blur, in out-of-focus areas of an image, or the way the lens renders out-of-focus points of light. Determining factors of bokeh are things like lens aberrations and shape of lens aperture. The term comes from the Japanese word boke, which means “blur or “haze”, or boke-aji, the “blur quality”. Here is a great compilation of bokeh photos. You will definitely enjoy it.