Your "What Matters: Communications" page shows the activity that’s most relevant to you. This includes replies to discussions you’re participating in, mentions, content people share with you, content you’re tracking in your activity stream, and direct messages.
Tips for getting the most out of your Communications page:
A number appears on your Communications icon in the top menu bar alerting you to the number of unread items awaiting you. You can see below I've got quite a few.
Click on an item in your Communications list on the left. A preview showing the most recent activity appears in the window on the right. Reply or comment directly from the preview pane, or click on the topic title to go to the entire content thread.
Icons next to the content alert you to the type of content in your Communications stream. Discussions, status updates, direct messages, etc., all have differentiating icons.
Quickly view your unread communications by toggling the Unread Only check box. Click the Mark all read link to dismiss all of your communications.
Filter your stream by mentions, direct messages, or shares by clicking the Filter drop down menu.
Send direct messages directly from your Communications page by clicking the Send Direct Message button in the upper right.
For more information, click the “?” next to the What Matters: Communications title.