Following are different activity tabs:
This page is the record of all your activities throughout the site listed in chronological order. If you’re logged in, there’s a status update box before the activity stream where you can post what’s on your mind.
This page shows all the @ mentions you received throughout the site.
This is a list of all the items (posts, comments, friendships, etc.) you have “favorited” in your Groups’ Activity Streams, the Sitewide Activity Stream, or even your own Personalized Activity Stream.
This panel shows all of your friends’ activities throughout the site.
This page shows all the activities recorded in the groups you have joined.