What happens to your Messages on my iPhone when I disable and delete Messages in iCloud?

For my iCloud storage, I have 0.3 GB left because 4.4 GB are my Messages. I want to free space in my iCloud. I was wondering this: What happens to your Messages on my iPhone when I disable and delete Messages in iCloud? Will all my Messages be deleted on my iPhone? I want as much information as possible before I make a decision.