Automatic focus
From The Glossary of Digital Photography
A function that enables most modern digital cameras to automatically determine the focus by moving lens elements. Many cameras allow the photographer to choose where in the image the focus point should be. The viewfinder may show four, nine, or even more focus points that can be selected by the photographer. Other cameras have many focus sensors and actually can determine where the photographer is looking and use that point to set the focus point. This feature is called eye control focus. See also eye control focus (ECF)
