Bokeh describes the rendition of out-of-focus points of light. Differing amounts of spherical aberration alter how lenses render out-of-focus points of light, and thus their bokeh. The word "bokeh" comes from the Japanese word "boke" (pronounced bo-keh) which literally means fuzziness or dizziness.
Images via Flickr and Etsy {click to enlarge and/or purchase}. Images 5 & 7 are my experiments with this photographic technique. View more of my photography in my Flickr gallery.
I've always been a fan of animation. I really enjoyed the section in our recent reading about the early studies of locomotion, primitive moving pictures and film animation techniques, including the creations of the Zoetrope, Praxinoscope, Phenakistoscope, and Stereoscope as precursors to the actual film projector.
As per usual, I went hunting for more information on these inventions via the Internet. These are just a few of the fascinating and beautiful examples I found...enjoy!