Can I go back to an earlier version of a card?

When a version is kept

Before saving an edit, Bardiyah checks whether the content actually changed. If it did, the previous state is kept as a version, and only then is the edit written.

So opening a card and closing it without changing anything creates nothing. The history stays a list of real edits rather than a log of you looking at things.

What a version holds

A version stores the title, body, image, and both the background and text colours as they were. It is a complete picture of the card, not just its text.

Restoring does not destroy

This is the part worth knowing: when you restore an older version, your current state is saved as a new version first, and the card is only then replaced.

If you restore by mistake, what you had written is not gone. It is sitting at the top of the version list. The version a restore came from is recorded too.

How many versions are kept?

All of them. There is no cap and no automatic pruning of old ones.