Statistics Canada conducts the Census of Population in order to develop a statistical portrait of Canada and Canadians on one specific day. The census is designed to provide information about people and housing units in Canada by their demographic, social and economic characteristics. You can read a brief history of the Census on the Canadian encyclopedia.
More details are available here: http://www.statcan.gc.ca/rdc-cdr/prcd-pvdr-eng.htm
Census microfiles for 2016, 2011, 2006, 2001, 1996, 1991, 1986, 1981, 1976 and 1971 are accessible in the RDCs.
As of July 2014 files with Dissemination Area (DA) & Forward Sortation Area (FSA) for these census files are also housed in the RDCs.
The historical Census files for 1951, 1941, 1931, 1921 and 1911 are also accessible.
List of variables for all census years.
2011: Census Dictionary, Illustrated Glossary
2006: Variables and codes, Census Dictionary
2001: Variables and codes, Census Dictionary
1996: Variables and codes, Census Dictionary
Variables and codes for 1991, 1986, 1981, 1976 and 1971: Please contact the analyst of your local centre to receive a copy of the variables and codes manual.