The MD5 Checksum is a computer algorithm that calculates and verifies 128-bit MD5 hashes generated from a specific file.
MD5 Checksum is used to verify the integrity of files, as virtually any change to a file will cause its MD5 hash to change. Most commonly, md5sum is used to verify that a file has not changed as a result of a faulty file transfer, a disk error or non-malicious modification.
Every file in the GDC contains an md5sum to ensure file integrity.
When downloading/uploading files using the gdc-client, an md5 checksum will occur to ensure that the file has been transferred successfully and with integrity to the original file.