Synology Office and Drive services are one of the most common apps used by all Synology users.
Formally Synology had all these apps as separate packages but over the years they have merged into one (well two) app.
Document, Slides, and Spreadsheet apps are already part of a package called Office, and to make things even more interesting once you install you will access it via the Synology Drive app.
This might be confusing at first but that's how the setup has been configured and this is not a DSM7 change at all, in case you don't use Office at the moment, but do use Drive (Dropbox alternative).
Whats new and different with Office and Drive in DSM7?
There are not many groundbreaking changes in these two apps but there are a few that are worth mentioning.
Drive has had more changes than Office so I'll start with that one.