Bokeh is the effect of blurring out the background. This is slightly incorrect in an important way. Depth of field has the effect of blurring out the backgrou

Bokeh is the effect of blurring out the background. This is slightly incorrect in an important way. Depth of field has the effect of blurring out the background and/or foreground; it is a property of optical systems. However, the design of lenses changes how this looks. The latter part is what "bokeh" means, and it is why people talk about "the bokeh" of a particular lens. In other words, bokeh is fundamentally an aesthetic characteristic.