The order of the publications is done by the Newest (Leftmost publication) to the oldest (rightmost publication), changing the order of publications allows the user to be able to keep track of whats new and up to date and what is old and could possibly do with updating, also allows for a more cleaner and more organized environment.
Starting in the Publications tab, click the Edit button or preview of a publication that you would like to move in the order. You will be greeted with the editing screen for the chosen publication.
While in the publication editing screen, click the Publication Settings link, on the left side, under the publication thumbnail. The next popup is for editing the publications settings, which been explained in another article called "Publication & Page Settings".
This interface is to edit the publications settings. In the Basic Information tab, in the right section, you will see a field called Date Publication. By default, this will state the date of when you created this publication. So if you created a publication right now, it will appear on the most left side of the ordering, whereas the one you created a month ago, will appear on the right side of it.
Example: Publication 1 = 1/6/2018(Left End), Publication 5 = 20/5/2018(Middle) Publication 98 = 1/3/2017(Right End) etc.
Publication 1 - Publication 5 - Publication 98
This function allows the user to order their publications based on the date that they have created that publication, making their workflow organized and clear.