The Activity Wall
The basic location for information, it’s also the home page for the website. The terms “Activity” and “Wall” are used interchangeably, with a subtle difference. When information is added to the website, it’s called an Activity (a verb) and it’s added to the Wall (a noun).
If you’re not logged in, you’ll see information that’s public in nature, such as blog postings and administrative notices.
If you are logged in, you’ll also see information relevant to the friends you’ve selected along with groups you’ve joined.