An activity stream is a list of recent activities performed by an individual, typically on a single website. For example, Facebook's News Feed is an activity stream read more...
Who made the action
With what object (Image, Text, File..)
Which action (Like, Comment, Published, Share...)
To which target (User, Event, Group..)
Each entity has its own news feed. A user, an event, a group but also entities that you can create for your own needs (dynamic entity). Each post with
PUBLIC visibility is also visible from the public news feed.
User create 3 posts:
POST 1which is published on an Event News Feed with
POST 2which is published on a Group News Feed with
POST 3which is published on a dynamic News Feed with
All the 3 posts are visible from the User News Feed. Only
POST 1 and
POST 3 are publicly visible.