Your Activity feed is a summary of everything that's happened in the team channels you follow. You can get caught up with everything fast.
-
Select Activity
to see your Activity feed. -
Bold messages have not been read. Select any to read the message.
-
Select the back arrow to return to the Activity feed.
-
Select Filter
to show only certain types of messages such as unread messages, @mentions, replies, and likes.
Source: Microsoft