Do you know that a cruise ship  is a passenger ship used for pleasure voyages?
I did! I've been on several cruises before! It is very nice.
Move of people in a cruise ship involves returning them to their original destination
Yes definitely. It is only meant to be a short trip to a destination via water.
There are some ship that  makes 2–3 night round trips without any ports of call.These types are called nowhere voyages
Oh I didn't realize that! 
On the other hand,  transport oriented ocean liners do line voyages