This document discusses task aggregation in SharePoint 2013 using the Work Management Service Application. It provides an overview of how tasks from multiple systems like Exchange and Project Server can be aggregated and accessed from a single location in SharePoint 2013. The key points covered include the prerequisites for task aggregation, how the service application handles caching and refreshing of tasks, and the client and server-side object models for developing against the service. Demos are provided showing how to interact with tasks through the object models and tamper with the underlying task provider model.