Let's say that you have published a form and shared it on the Internet. Folks are filling out this form. We say that the form is in a published state.
Now, you need to make some changes to the form. However, you don't want all these changes to be live so that others can see them. That's because you are still working on the form. We say that the form is in a draft state.
When a form is in a draft state, others can't see the changes made to it. They will see the form as it was published. Once you are happy with all your changes in the draft state, you can click on Publish to publish the changes made to the form. Now, others can see the changes made to the form.