However for the International Year of Statistics (2013statistics.org) there's a practical set of definitions which encompass that scope:
- The science of learning from (or making sense out of) data
- The theory and methods of extracting information from observational data for solving real-world problems
- The science of uncertainty
- The quintessential interdisciplinary science
- The art of telling a story with [numerical] data
So broadly the science of collecting and analysing data, and increasingly in so many areas that impact on everyday life. Again the International Year of Stats has helpfully distil that big picture purpose too, focussing on the increasing government and business appetite for properly data driven decisions across that touch our lives in so many ways.