depth of field
The smaller a depth of field you will see1/3 of the image.
the mid depth of field you will see 2/3 of a image.
Depth of field of an image is what part of the image is in focus so if you have a small f stop like 5.4 then only a 1/3 of the image will be in focus so if you have a medium depth of field which is 16 f stop then you will have 2/3 of the image is in focus and if you have a large depth of field then you will have an f stop of 32 and the whole image will be in focus.