The word “bokeh” (pronounced like “bouquet”) may be new to you. You’ve certainly seen bokehs in photographs all of your life, you just may not have realized that there is a word for them.
Bokeh describes the rendition of out-of-focus points of light.Ken Rockwell says the following about bokehs.
Bokeh describes the appearance, or “feel,” of out-of-focus areas. Bokeh is not how far something is out-of-focus, bokeh is the character of whatever blur is there.
This article How to Take Beautiful Bokeh Christmas Images [With 39 Stunning Examples] tells you how to make your own beautiful Christmas (or any other time of year) bokeh photographs.