The tabs are displayed on the pages from left to right. The order of the tabs is determined by the Design Canvas. The first tab listed in the Design Canvas is the first tab on the left side of the page. The second tab listed is the second tab from the left on the page. In short, the vertical location of the tabs in the Design Canvas determines where it is displayed horizontally on the page.
If the tab order is incorrect, click on the tab’s title, then drag and drop the tab to its correct location. A space will open for the tab and its buttons. The tab and its buttons will move to the new location. Once the Publish button is clicked, the new ordering will be locked into place.