Firstly a panorama or panoramic tile. (Please don't further complicate this by confusing this with a live tile though.)
This is the very wide display (typically 4 screen widths wide) that the user can swipe from side to side to navigate. Vertical scrolling is not supported. The background is typically a single picture.
Sample/Example panorama from the UI Design and Interaction Guide for Windows Phone 7 v2.0
A built in control will be provided for developer use in the next/RTM version of the SDK. But, for now, a very good alternative (and very similar to what will actually be shipping) can be found at http://phone.codeplex.com/.
So that's a panorama. It's simply a display and list control for use within an application.
So what about hubs?
Hubs are special applications which come on the device and serve as a central point for collating content, information and applications which are all focused on a single area.
The phones come with 6 built in hubs:
- People: for contacts and social media update integration, etc.
- Pictures: for photos taken on the device and synced from facebook or live.com
- Office: for OneNote, Word, Excel & Powerpoint
- Games: for all games (unsurprisingly) and including XBox LIve integration.
- Music + Video: no prizes for guessing what goes here
- Marketplace: for buying lots of lovely apps, games, music, etc.
As an aside it may be useful to note that only the 'Pictures' and 'Music + Video' hubs offer any level of third party application integration.
So why the confusion?
Because all hubs use panoramas in their main screens.
I strongly suspect that as developers couldn't make their own hubs, nor have they been provided a panorama control, this has no doubt led to the grouping together of these two things in peoples minds.
Well yes. It seems that developers may be able to develop their own hubs in the future after all...
Windows Phone 7: Developers can build their own hubs
Windows Phone 7: Microsoft explains and expands hubs
Has that cleared things up now?