Depth of field (DOF) is the amount of distance between the nearest and farthest objects that appear in acceptably sharp focus in a photograph. The depth of field varies depending on camera type, aperture and focusing distance. DOF is one of the most creative and profound effects available to photographers.
Photo by Niyazi Ugur Genca
In simpler term, we define depth of field as the zone of sharpest focus in front of, behind, and around the subject on which, when lens is focused on a specific subject; with TTL (through the lens) SLR camera, DOF can be previewed in the viewfinder of a camera – the preview is very handy for critical type of work. For an example, when taking a product shot, when you require absolute certain if DOF is adequate to cover the object you intend to photograph Generally, the closer the subject to the camera, the more evenly with the distribution of depth of field in front and behind the subject. As distance of focus extends, DOF usually will be more behind than in front of the focused area.
You can use Depth of Field Calculator to understanding dept of field.
