The word bokeh comes from the Japanese word for blur. In photography though it is more than just this, it’s the quality of the blur. There are certain elements however that determine if it is bokeh, or just plain old blur.
Have you ever looked at a portrait photo in a magazine, book or online and been amazed by the soft out of focus and blurry background. This is usually the result of focusing on your subject and using a wide open aperture. Or in other words, an aperture with a low f/ number. A wide aperture helps to isolate the subject and throw the back ground out of focus. As a rule anything from f/4 and lower will create this effect. Having said that, the lower the f/ number at say f/2, the more the background will be thrown out of focus and look blurry.
