Depth of field is one of the most crucial fundamentals in photography. Depth of field (DOF) can be used in different ways, even on the same image subject, to completely change the composition of your image.
You can use DOF to put focus on a certain subject in your image and take distractions such as the background or surrounding “noise” out. Or you can do the exact opposite and put a texture on the whole image and have everything in your photo in focus which is commonly used in landscape photography, and of course everything in between all with a little adjustment of your Aperture or “f-stop”
The aperture setting is the size of the hole allowing light to enter the camera. With this in mind remember that:
larger aperture hole = small depth of field = smaller aperture setting (ex: 3.5, 5, ect.)
Smaller aperture hole = larger depth of field = higher aperture setting
Short DOF is my personal favorite method of photography and is great for putting emphasis on a certain part of the image and It can leave the rest of what’s in the image up to the imagination which can also make an image more interesting. Also note that it makes every detail on the object in focus pop that much more creating further emphasis on a subject.