Data federation and data virtualization are both terms that have been coined to describe the process of collecting and compiling data. Data virtualization is a superset of the ten-year old data federation technology. It also includes the advanced capabilities of performance optimization as well as self-service search and discovery. Data federation is a distributed access to data residing in multiple systems with the purpose of joining the data together as if it came from the same system. Data virtualization on the other hand, has evolved from data federation by improving performance and adding other advanced capabilities such as self-service search and discovery. Advanced data virtualization products like the Denodo Platform have evolved to include dynamic query optimization techniques to determine the best query execution plan thus delivering optimal performance times.  Read more at: http://www.datavirtualizationblog.com/leading-analysts-mixing-data-federation-data-virtualization-terms/