Post Revision Optimization
Whenever you save a page or post in WordPress it creates a revision. This occurs in both drafts and already published posts that are updated.
On large sites, this can add up very quickly to thousands of rows in your database which are not necessarily needed. And the more rows you have the larger your database in size, which takes up storage space.
It is not uncommon for older sites to have 100+ revisions on their main pages. This is simply due to years of editing and updating content.
Let’s say for example a site has 700 pages or posts with 150 revisions on each, this would be over 100,000 entries in the database. Post revision optimization helps to ensure the performance of your site isn't affected.