The idea
Automatic version snapshots of your document while you write: at most one every ten minutes of writing, and one at the moment you submit to an assignment. Browse a timeline of previous versions, see what changed, and restore an earlier one. No manual saving of "v2_final_FINAL" copies.
Why it matters
Autosave is great until you accidentally delete a paragraph and don't notice until the next day. Version history is the safety net that makes autosave feel safe. It's also useful for tracking how your argument evolved: sometimes you want to go back and see what you wrote yesterday before you restructured the introduction. For collaborative documents, it's even more important: you can see what changed and when.
Availability
Shipped. Folio records the snapshots on every plan, Scholar included: they are the writing record your Integrity Certificate, your authorship report and an instructor's view of a submission are built from, so the record of how a document was written never depends on a paid plan.
Browsing that timeline, comparing versions and restoring an earlier one is part of Fellow and Chair; on Scholar the snapshots are still recorded, and upgrading opens the whole timeline. Open History in the editor's top bar to see the newest 50 versions. Pick one to see What changed (a word-by-word comparison with your current text) or the Full version. Restore this version, then Confirm restore, brings it back; Folio snapshots your current text first, so a restore can itself be undone.
On every plan, a local draft is also kept in your browser as a crash safety net, so autosave is never your only line of defense.