The site requires that you check a page out of the locked archive before it can be edited.     This means that every change is recorded and a version history can be maintained. 

When you have checked a page out you will have exclusive access to the page for editing.   All other users will only by able to see the content, they will not be able to edit it.

Once you have edited the page and you are happy that the content is suitable for publication, you should check the page back in to the repository and submit the page for approval.