A family of Microsoft word processing software products for creating web, email, and print documents.
Good point, a subscription isn't necessarily required. But without a subscription, editing will only be available on screens of certain sizes. See https://support.microsoft.com/en-us/office/what-you-can-do-in-the-microsoft-365-apps-on-mobile-devices-with-a-microsoft-365-subscription-9ef8b63a-05fd-4f9c-bac5-29da046833ea.