Redundancy: refers to the amount of wasted space consumed by storage media to record picture information in a digital image.
Spatial redundancy: elements that are duplicated within a structure, such as pixels in a still image and bit patterns in a file. Exploiting spatial redundancy is how compression is performed.
Temporal redundancy: pixels in two video frames that have the same values in the same location. Exploiting temporal redundancy is one of the primary techniques in video compression.
Robert Foxx 