The page history lets you browse previous versions of a page. To access the page history, click the Page history button on the toolbar:
This will open the page history window:
Browsing previous versions
On the left of the page history window is a calendar. Dates with previous versions of the page are highlighted in orange. On the right is the list of previous versions, with the current version at the top. Clicking a date in the calendar will scroll the list to show versions from that date.
Previous versions are kept for a year. Versions more than a year old are shown in grey. Note that previous versions have only been recorded since 23rd January 2020.
Viewing and editing previous versions
Click the View button next to a version to open it in a new tab. A banner at the bottom of the page shows that you are viewing a previous version and includes links to edit that version or switch to the current version:
You can edit a previous version in the same way as a normal page. If you click to save the page, you will be asked to confirm that you want to overwrite the current version of the page with the previous version. Alternatively you can copy content from the previous version and then paste it into the current version of the page.