How do publishing and drafts work?

Your edits collect as drafts rather than going live one by one. As you work, a count of unpublished changes builds at the top of the toolbar, and a bar sits along the bottom of the page to remind you. Nothing you have changed is visible to visitors until you press Publish.

When you publish, every pending change goes live together. You can review the whole list first, and if you change your mind you can discard all of it and start again. Publishing is always something you do on purpose, never automatic.