Deleting revisions and reducing database size
Revisions are automatic saves of your work done by Wordpress, in case you want to go back to a previous form of your writing or if something goes wrong with the internet etc. While good, they are made every single time you modify something. And that means they can pile up, even in the hundreds as I've had in the case of some posts. If too many, they are useless and need to be deleted, because they increase the size of your database without reason.
As shown in the image, I have 16 revisions of the same post, that I have published, meaning I am content with it, I don't need more than 2 or three revisions of it.