Bokeh is a japanese term for the aesthetic quality of the blur produced in the out-of-focus parts of an image produced by a lens. Generally, prime lenses with large aperture create excellent boken.
The above paddy filed image was taken with a Nikon 50 mm prime lense . The purpose of taking this image was to focus on close up of paddy crop by using a larger aperture (in this case F- stop of f/1.8) and blurring the background.
Third eye view 
Bringing a canon into the mix, I have planned to fall in love with my 50mm 1.8 it has already begun. Lovely, effective image
I love my Nikon 50 mm prime lense. For vegetal subject, I find it a must!
I LOVE this effect. I use it probably more than I should but I love it when there is a specific focal point in a photo and the bokeh helps to ensure that the eye goes straight to the subject.