What is statistics? And census?​

A census studies every member of a population. ... Basically, a parameter contains information about everyone in the population while a statistic only tells you something about a small part of that population (How to tell the difference between a statistic and a parameter).

Statistics:-

Statistics is the science concerned with developing and studying methods for collecting, analyzing, interpreting and presenting empirical data. Statistics is a highly interdisciplinary field; research in statistics finds applicability in virtually all scientific fields and research questions in the various scientific fields motivate the development of new statistical methods and theory. 

Census:-

Census, an enumeration of people, houses, firms, or other important items in a country or region at a particular time. Used alone, the term usually refers to a population census—the type to be described in this article. However, many countries take censuses of housing, manufacturing, and agriculture.

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