The 1901 & 1911 census records for Cork are now freely available online. The National Archives has digitised the records, with the help of Library and Archive Canada.
They are an invaluable resource for tracing ancestors, teaching local history and researching social and economic conditions. For every household, the records contain the names, ages, relationship to head of household, marital status and county or country of birth. I addition, it gives years of marriage, number of children born alive, ability to read and write as well as languages spoken (English/ Irish).
As well as households, details are given for hospitals, boarding schools, barracks, workhouses and other institutions. The census also details houses and buildings including condition. People can use census details like age and years of marriage to locate birth and marriage certificates, giving more information about ancestors right back to 1664 when civil registration began.