Bokeh is a funny little term used to describe the quality of light in the parts of an image that are out of focus. Depending on the shape of the lens aperture, the out of focus portions of the image can be rendered more pleasing by some lenses than others. The quality of the bokeh is most significant when the background is not completely blurred. When the background is completely blurred, it's all one uniform color. I do appreciate photos like this; the subject stands out against a solid color. But when there's some definition to a blurry background, I think you can get an added benefit. The background is out of focus so the subject can still stand out, but the background still provides a setting for the subject that allows the background to still be interpretive within your image. So as you consider the background of your images, consider ways to use it to your greatest compositional advantage, and if you can get some nice bokeh in the background, all the better.