Original camera data never should be transferred using a simple file copy (e.g. with macOS Finder, Windows Explorer or a simple command line copy). To protect yourself from a really bad experience – like having lost a day's worth of footage because missing or corrupt files weren't noticed before the original recording media had been erased – your minimum standard should be checksum-verified data backups.
Checksums
A checksum is a small block of data that represents a file for the purpose of detecting errors that may have been introduced when the file was transmitted. There are different types of checksums, which are calculated with different algorithms, but all for that same purpose.
A data management tool which offers a "checksum verify" will calculate and compare the checksum of a file versus the checksum of its copy. The result of the verification (verified or failed), along some additional information then can be stored in checksum directory listing called media hash list (MHL).