According to PhotoGuide japan (Bokeh is a japanese word), Bokeh is "the way the lens renders out-of-focus points of light". With a look at the photo below, you will understand what it means.
Today the lizard brings you "Do It Yourself" links that will teach you how to shape your Bokeh:
Ari Takes Pictures - DIY Bokeh or “how to make pretty stars”
DIY Photography - DIY - Create Your Own Bokeh