What does 'bokeh' refer to in photography?

Bokeh refers specifically to the aesthetic quality of the blur that occurs in the out-of-focus areas of an image. It is not merely about having a blurred background; rather, it encompasses how that blur looks in terms of smoothness, texture, and the visual aesthetics of the circles and shapes created by the lens in those out-of-focus areas. Photographers often take great care in achieving desirable bokeh effects, as it can enhance the subject's focus and contribute to the overall mood and atmosphere of a photograph.

While processing speed, color contrast, and linear perspective are all important concepts in photography, they do not pertain to the specific and nuanced characteristics of blurred areas in a photograph, which is what bokeh fundamentally describes. Understanding bokeh allows photographers to make informed decisions about lens choice, aperture settings, and composition, ultimately leading to more visually appealing images.