Rsync is an extremely intelligent and useful command for copying files between systems and it can resume or repair corrupted downloads as well.

Sharing some commands for my own reference:

rsync [options] [source] [destination]
rsync /folder1/file /folder2/file (local copy)
rsync -e ssh /localfolder/file

Interesting options:

-z (enable compression)
-v (verbose)
-r (recursive)
--progress (shows speed/progress of download)
--append (adds at end of copied file, useful for resuming)
--partial (keeps downloaded file saved as hidden for resumption)