The cutter is basically a sloop. The cutter had only 1 mast and was only 70 feet on average. The sail plan varied. One was a square sail and then gaff rig jibs and spanker. The other was gaff rigged jibs and spanker. A cutter is a one-masted fore-and-aft rigged vessel with more than one jib (staysail) before the mast.
If there is only one jib, the boat is a sloop.