Trump is blockading Iranian ports in the Persian Gulf. What does that mean?

A former Pentagon official said the goal of the U.S. blockade is to get the Iranians to back down and restore freedom of navigation to the strait.

Trump is blockading Iranian ports in the Persian Gulf. What does that mean?
A former Pentagon official said the goal of the U.S. blockade is to get the Iranians to back down and restore freedom of navigation to the strait.