Differencing of general binary files goes under the rubric of delta encoding, with a widely used example being the algorithm used in rsync.
A high-efficiency (small patch files) differencing program is bsdiff, which uses bzip2 as a final compression step on the generated delta.
An example of this is in diff, which shows which lines changed, and where the context format allows robustness and improves human readability.
Other concerns include computational efficiency, as for data compression – finding a small patch can be very time and memory intensive.
When one wishes to emphasize the connection, one may use the term differential compression to refer to data differencing.