A patch is a list of deletions, additions and changes that, when applied to an original file, produces a modified file.
If the original and modified files are big, instead of storing them both, you can compare them, export the patch file, and store the original file along with the patch. Since the patch only contains the differences between the original and modified file, it is usually much smaller. Applying the patch to the original file produces the modified file again.
To export a patch:
- Compare two files or two texts by lines. The standard .patch file format works with lines. Comparing by any other metric is not supported.
- Select File > Export Patch.