Depth of field is a useful composition choice that determines how much of the picture is in focus. When the background is blurry with the subject in focus, this is a shallow depth of field. However, when the whole photo is in focus, this is a deep depth of field. Depth of field is useful for focusing the viewers’ attention on a specific area of the photo. It also brings more attention to your subject by making the background soft and blurry.
Some ways you can control depth of field are by changing the aperture/f-stops on your camera. The smaller your aperture is, the deeper your depth of field meaning that more of your image will be in focus. The size of your camera lens also impacts the depth of field of your photos. A useful camera mode for shooting for depth of field is aperture priority mode, which allows you to choose the aperture you want while the camera automatically picks a corresponding shutter speed to give you good exposure.