Microsoft Office 2019 is a perpetual license, it only includes desktop applications (Word, Excel, Powe PointPoint, Outlook, OneNote) and does not include online services. It is licensed for a workstation (1 workstation, PC or Mac).
Microsoft 365 depending on the version selected, also includes on-line services, such as Microsoft Exchange e-mail, Teams messaging, SharePoint, virtual OneDrive and online versions of traditional applications from the Office suite. The Microsoft 365 subscription is limited in time (one month or one year) and must be renewed. The license allows the application to be used by only 1 user, on 5 workstations (PC or MAC), 5 smartphones and 5 tablets.