Depth of field :Depth of field is a measure of how much of a scene (from the front to the back of the image) will be in focus. Although not strictly digital photography terminology, the affect still applies to digital cameras.
OOF ;photography term that refers to the way a lens blurs an image.
Generally it is considered good practice, especially with potrait photography, to have the main subject in focus and the background blurred.
Soft Focus Lens: A special lens that creates soft outlines in the imag, This can all so be created by software.