This image, of the yellow flowers, is and example of maximum shallow depth of field. the main focus is the flowers so they used shallow depth of field to eliminate the distracting background.

This image, of the railway station, is an example of maximum depth of field because all of the subjects are in focus. They used a smaller aperture to ensure that every single element of the picture is sharp.

The image, of the red flowers, is an example of shallow depth of field. they red flowers are the main focal point in the image, meaning that the other distracting elements such as the background were thrown out of the image.

The image, of the building, is an example of maximum depth of field. they used a smaller aperture to include all of the elements into the image including the framing tree line.