At its core, is a binary diff tool. Unlike a standard "update" that might replace an entire file, xdelta looks at two versions of a file (the original and the modified) and calculates only the differences between them.
To generate a patch, you use the -g option followed by the names of the original file, the modified file, and the output patch file: xdelta online patcher
: The original, "clean" version of the file (e.g., a .iso , .bin , or .nds ROM). Patch File : The .xdelta file containing the modifications. At its core, is a binary diff tool