Depth of field (in photography) is the distance between the nearest and farthest objects in a scene that appear acceptably sharp in an image. A camera can only focus its lens at a single point, but there will be an area that stretches in front of and behind this focus point that still appears sharp. This zone is known as the depth of field. It’s not a fixed distance, it changes in size and can be described as either ‘shallow’ (where only a narrow zone appears sharp) or deep (where more of the picture appears sharp).
This is a good example of deep and shallow depth of field (everything is in focus or just one object in focus)
As to bullet journaling, I believe we should use bulleted text.
This is an example.