I don't really understand why this spell requires concentration.
"It lasts for the duration or until a wind of moderate or greater speed disperses it." So, the spell lasts for the duration. But why do we concentrate? In other spells, if you break the concentration the spell disappears. Specifically, I want to know if "lasts" means "stay in place." If that is true, then breaking concentration means you can't move it.
The spell's description also says that "the cloud moves 10 feet directly away from you in a direction that you choose at the start of each of your turns." Assuming the spell lasts and the cloud moves for the duration, do you need to maintain concentration?
I play in French, and in that translation the problem is the same. Is the way I am understanding it the same as in the English version?