imo, stand off weapons can be employed at a distance from the
target that reduces the launching platform's risk of coming under
direct fire from enemy units. one think i'm unsure of is whether
weapons falling under this classfication has to be guided.
cruise missiles are just low flying missiles with a (usually)
standoff range, with guidance systems such as GPS and usually
contains an in built inertial navigation/guidance system. It would
be considered as a standoff weapon.