Let's say that you have published a form and you have 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. As you are making changes to the form, you don't want all these changes to be live to be seen by others. 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, then others can't see the changes made to the form. They will see the form as it was "published". Once you are happy with all your changes in the "draft" state then you can click on "Publish" to publish the changes made to the form. Now others can see the changes made to the form.