A revision is a saved snapshot of a post or page at a particular point in time. WordPress automatically creates one every time you save or update your content, building a running history of changes.
This means you can look back at earlier drafts and, if needed, restore an older version — useful if a recent edit didn’t work out the way you hoped, or content was accidentally deleted.
Viewing Revisions
You can find the revision history in the editor’s sidebar under document details. It shows a list of saved versions along with the date and author, letting you compare and restore a previous version with just a couple of clicks.
A Practical Consideration
Revisions are stored in your database, and a heavily edited post can accumulate a surprising number of them over time. Some site owners choose to limit how many revisions WordPress keeps, which can help keep the database a bit leaner on very active sites.