What makes a ship sail on sea water?

Question

You saw, how so heavy ship sails from port to port carrying a lot inside. Huge containers, is it very simple ? A simple engine makes it to sail ? Ever you thought it ? Share with me.

Answer 1

They sail on salt water because they can't get to where they want to go via fresh water.

The rest of your question makes no sense to me, unless you are asking what they use for power. They use large diesel engines or large steam engines.  They do NOT use sails.

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