You can try bold changes on your site without worrying. Every edit, whether the agent made it or you did, is saved as a numbered version. Going back takes one keystroke or one click, and going back never throws anything away.
With the preview in front, press ⌘Z to undo the last change and ⌘⇧Z to redo it. Undo and redo are saved as versions too, which means they survive a page reload and work the same in every browser tab. Each one is named for what it brought back, for example “Undo to version 4 (from 5)”.
Pressing ⌘Z again keeps stepping back through your real changes. It does not flip between the last two states.
Your site returns to that state and the restore is recorded as a new version named “Restored version 4” (with your own number). The versions after it are kept, so you can always come back to the state you just left.
Rarely, a version's files were never saved. You will see “Version 7's files weren't saved, so it can't be restored.” (with your own number). Restore the version just before or after it instead, and contact support through Chat with support in the Help menu if it keeps happening.
For the rest of the workspace, see The editor at a glance.
