Sheldon M. Ross in his book, "Introductory Statistics" states the definition of statistics to be:
"Statistics is the art of learning from data. It is concerned with the collection of data, their subsequent description, and their analysis, which often leads to the drawing of conclusions."
Why is it an art and not a science? The definition of art states that it deals with creativity, while the definition of science says it deals with the systematic study of a structure, in our case, data.