Focus stacking (also known as focal plane merging and z-stacking or focus blending) is a digital image processing technique which combines multiple images taken at different focus distances to give a resulting image with a greater depth of field (DOF) than any of the individual source images.
A technique called focus stacking, also referred to as focal plane merging and z-stacking or focus blending, combines several images captured at different focus points to create a single image that has a broader depth of field compared to the original photographs.