bokeh

I I bokeh is blurring the background. It's the effect of the blur that makes it look a certain way. It's the way the lense renders out of focus points of light. 

Photographers like this because it focuses in on a subject really well and makes the light look aesthetic. 

In order to maximize bokeh in a photographers in their images they must buy a lense that has auto focus or that has fast shutterspeed and a small aperture. It needs to be able to be adjusted so you can easily get the effect. it should also have a longer lense so there can be greater distance between the subject and the background.