First time I heard the word Bokeh was when a japanese photographer mention it about an image of mine. I ask him what was the meaning of it, he answered that there are no translation, but what it means is how some lenses because the design of their diaphragm renders polygonal figures in the reflexions or highlights that are out of focus, and a good Bokeh is that that keeps it's shape even if the focus goes really out. As I understood, Bokeh is kind of "mood with a shape".

Now I discover out of the web page mentioned that it is something so complicated that need an explanation the lenght of some pages full of diagrams and formulas.

The photo Bird of Paradise enclosed is an example of what I think Bokeh means.

the lense is a Carl Zeiss Distagon f 4, 50 mm