Despite the name, Office for iPad is three separate apps - Word, Excel and PowerPoint - which are individually available in the App store.
The apps have a familiar interface, with the same Ribbon interface and layout. But at the same time, they're not just a port of the regular desktop version. Menus have been optimised for touch; objects can be dragged, rotated or resized with a swipe, and the interface scales properly in both portrait and landscape mode.
There's solid integration with other iPad features. You can use voice dictation to create a document, perhaps, or AirPlay to project your finished presentation.
You get plenty of functionality, too. This isn't the hobbled Office Mobile for iPhone: there are templates, tables, footnotes, filters, charts, transitions and just about everything else you'll need. Everything is very configurable, formatting is preserved so documents look just as you'd expect, and of course you can save and share your documents in OneDrive, OneDrive for Business and SharePoint.
If you're just looking for a viewer, then the good news is that the Office apps are free. Just download them and you'll be able to read and present documents, spreadsheets and presentations.
To create or edit documents, though, you'll need an Office 365 subscription. If you have one already, no problem; you're covered for all the apps installed on up to 5 tablets, as well as 5 further Office installations on your PCs and Macs.
If you're not a subscriber, Microsoft says Office for iPad will be covered by the upcoming Office 365 Personal at $6.99 a month ($69.99 a year).