Pablo8 wrote:
Depth of Field, is the amount of the subject matter that is in acceptable focus. Depth of Focus is the range of focus in front of, and behind the Film / or Sensor receptive surface. The two terms are all too often, mixed up by people. But they are different things. Please raise your hand if you cannot grasp the difference.
Depth of focus can be confusing to many. It is explained pretty well here: