trying to find out if there is a command similar to "ditto"

trying to find out if there is a command similar to "ditto"

I know if I want to in a sense merge one directory into another without
over writing everything in there using ditto. But now I am trying to see
if there is a way I can compare both directories.
From one directory I am copying over to another directory frequently. But
from the origin directory I sometimes delete stuff, which running ditto,
doesn't apply to the folder I am copying/merging things over to.
So is there anything similar to ditto that can at least print out the
differences between the two directories so I can remove any files I may
need to remove from the directory I am copying over to..