The definition of a voyage is: a long distance journey made by sea.
And the definition of a cruise is: a voyage on a ship or boat taken for pleasure or as a holiday and usually calling in at several places.
I've taken both adventurous expeditions by small ships to remote places and large cruise ships, where the individual chooses the extent of their own experience. The small-ship voyage serves not only as a learning experience, but a way of leaving one's comfort zone and challenging oneself to explore the unknown. The cruise ship provides an environment that is essentially the holiday. One may or may not choose to leave the ship to explore the short stays in foreign ports and there are plenty of activities to fill the days at sea, whether moving or stationary.
Although I prefer the small-ship option, it tends to be an expensive choice, whereas the large-ship cruises are reasonably-priced, even cheap if one selects the inside cabin choice and doesn't drink alcohol.
Click on the images below to read about my adventures at sea.