It's so dumb that Microsoft itself acknowledges the dumbness, having to list Microsoft 365 as "Microsoft 365 (Office)" on various app stores, because they know how much confusion they've created ...

Microsoft Office is a pay once ... especially the 4K monitors and ultrawide monitors near the bottom of this list.

You can run Microsoft Office, including Word ... the ability to set custom categories for incoming mail or mailing list, and automatic replies, where 365 offers these features.