This document introduces linked data and its benefits for answering complex questions across distributed data sources on the web. It explains that by giving every data element a URI, different databases can expose their data as resources with properties and links. This allows data from multiple sources to be queried together by following links to answer questions that require integrating information from different datasets. Examples show how linked open data from over 40 datasets can be used to answer very complex questions that require combining data from different domains. Potential use cases highlighted include mobile applications and applications in life sciences and healthcare that require integrating diverse data sources.