Although Chatter data is accessible in Apex using SOQL queries, Chatter in Apex provides a simpler solution. It consists of a series of Apex classes called
ConnectApi that expose Chatter features in a simpler way, as an API rather than a data model. With Chatter in Apex, Chatter data is preformatted for display, and many features can be accessed with a single method call. Using the data model is typically not as easy or concise.
For more information about Chatter in Apex, visit the online documentation at http://www.salesforce.com/us/developer/docs/apexcode/Content/apex_classes_connect_api.htm.