When you have added some basic content to your site and you want the public to view it, then you are ready to publish it. To do so, just use the Publish button in the upper right corner of the editor. There will be a pop-up congratulating you on publishing your website.
Even after publishing, you can update your site as often as you want. You can make edits to text, add SEO tags, create new pages, change your theme, etc. Every time you want those changes to appear on your live site, click on the Publish button.
Un-publishing Your Website
If for any reason you want to take your website offline for say a bit of time, you can unpublish it.
To un-publish it, simply go to the settings tab in the editor, click on General and then scroll to the bottom. You will see your Unpublish button.
You can still publish your wwebsite anytime, even after unpublishing it, by clicking the Publish button.