From pure science to social science, wherever experiments are being conducted, a lot of data is collected. In every research a lot of data can be collected, but for our purpose which data will be more useful and how to draw conclusions from that data is taught in Statistics. By studying statistics we become proficient in the use of statistical tools and concepts for quantitative reasoning which helps us in extracting information intelligently from the sea of data.
For example if you want to know how good are the students of a particular class, you may use pass percentage of the class, average marks scored by the class, or you may create certain ranges of marks and put number of students against those ranges. In so many ways you can judge the performance of a class. If you are well grounded in Statistics then you know for what purpose you want to judge the performance and accordingly you will choose the measure to judge the class.