"Free to Keep" refers to games that Steam occasionally offers at no cost for a limited time. When you claim a Free to Keep game during its promotional period, it becomes a permanent part of your Steam library, exactly like a game you've purchased. You can download and play it whenever you want, even after the promotion ends.

These publisher-initiated promotions typically run for less than a week, though the duration varies. It's essential to claim the game before the publisher's offer expires if you want to keep it forever. The games you get through these promotions are identical to their paid versions and will receive the same updates.

Free to Keep offers are subject to availability, as indicated by the "while supplies last" disclaimer. Games obtained through these promotions don't generate Steam Trading Cards, and some games might have certain features or content limitations.