STCW is Standards of Training, Certification and Watchkeeping. It is an endorsement required for international work, an effort to bring countries toward a single standard. Countries may still have National licenses good only within their waters.
It is required 1/1/2017. So it is not a license per se but a required endorsement on a license with it's own specific rules.
It's also been quite a money maker for schools with all the captains taking courses to bridge the gap.
Many commonly use the term STCW licenses but the correct term would be STCW endorsed licenses or licenses with STCW endorsements.
