md5sum stands for message digest version 5, which is used to check file integrity whether the transferred files are corrupted or not. md5 is a command line utility used in both LINUX or MS-DOS/WINDOWS which generates and verifies message digests using the md5 algorithm. The md5 hash comparison detects changes in files that would cause errors. The possibility of errors is proportional to the size of the file. The possibility of errors will increase with the increase in size of the file.