TORONTO -- The 2021 census has already landed in the mailboxes of millions of Canadians across the country, and the online version is ready to go ahead of Census Day on Tuesday.

So what do Canadians need to know to complete the first census ever delivered during a pandemic?

WHAT IS THE CENSUS?

The census is an important part of Canada鈥檚 history, helping to form a picture of the country and provide the data needed to shape public policy and address inequities.

It isn鈥檛 just to assess population gains. By receiving responses from communities in every province and territory, the government can get a greater picture of the diverse needs of the public.

There is the Census of Population as well as the Census of Agriculture, which is handed out at the same time to collect data on every agricultural operation in the country.

Since 1971, the census has been held every five years, with the last one being held in 2016. That year saw the return of the mandatory long-form census, after it had been removed by former prime minister Stephen Harper in 2010 in favour of a voluntary National Household Survey that resulted in some data gaps.

There are two versions, the short-form and the long-form census, distributed randomly, and every household receives either the short-form or long-form Census of Population.

HOW DO I FILL IT OUT?

Households can fill out the census either on paper or online. Each household will receive the census in the mail, and a secure 16-digit access code can be found on the paper copy.

Those who wish to fill out the census online can navigate and input their secure access code to begin the process. On its website, StatCan says it is hoping 80 per cent of Canadians will fill out their census online, calling it 鈥渢he best way to stay home and stay safe while fulfilling your census obligation.鈥

Answers are confidential, and it is safe to fill out the census online, StatCan says.

WHAT IS THE DIFFERENCE BETWEEN THE SHORT AND LONG-FORM?

Around 75 per cent of Canadians will receive the short-form census, while 25 per cent will receive the longer version.

The short-form version asks basic demographic questions regarding things such as age, language and marital status.

The long-form version goes into more detail beyond just those questions, gathering 鈥渋nformation about the social and economic situation of the people across Canada and the dwellings they live in,鈥 according to StatCan鈥檚 website.

A full list of the long-form census questions and why they are asked

WHAT IS DIFFERENT THIS YEAR?

鈥淥n the short-form, there鈥檚 three new types of questions. There鈥檚 the gender identity, veterans and new questions on official language minority,鈥 Geoff Bowlby, director general of the census program told CTV鈥檚 Your Morning.

鈥淥n the long-form, you get all of those, plus some additional questions on labour market, commuting to work, and some changes to the Indigenous identity questions.鈥

One of the big updates is to provide a better picture of gender diversity in Canada.

In past years, Canadians could only choose either 鈥渕ale or female鈥 when asked for their sex. After engaging with the LGBTQ2S+ community following the 2016 census, the question , in part to address data gaps on the transgender and non-binary communities within Canada.

Now, Canadians will answer two questions: their 鈥渟ex at birth鈥 and then their gender. On the census, Canadians will choose between 鈥渕ale and female鈥 for 鈥渟ex at birth鈥 but in the section regarding gender, they can choose male, female, or write in a third response, providing space for non-binary Canadians to identify themselves.

Bowlby added that in the past they have sometimes aggregated data from the census regarding race into broader categories such as 鈥渧isible minorities鈥 even though past censuses did ask specific questions regarding ethnicity and race.

鈥淚n this upcoming census, however, when we disseminate the data, we鈥檙e going to go through a great deal of what we refer to as 鈥榙e-aggregation鈥, or stop lumping people together into one category, put them into the categories that represent them best,鈥 he said.

HOW DOES COVID-19 FACTOR IN?

Some of the changes this year to the long-form census in particular are related to the pandemic itself.

There are new questions about the labour market, asking Canadians if they worked the full year, or only part of the year, and asking them the reasons they may have lost work.

鈥淭hese are the kinds of questions that will allow us to see how badly the pandemic impacted local communities and the labour market,鈥 Bowlby said.

HOW LONG DOES IT TAKE?

The short-form census takes only a few minutes, while the long-form is around half an hour, with time varying based on how large your household is.

However, there鈥檚 another way to measure the time passing.

StatCan has for you to listen to while you fill out your census, ranging from pop stars like Shawn Mendes to spotlights on Indigenous and Francophone artists.

Filling out the census will 鈥渢ake you about seven or eight songs for a typical household,鈥 Bowlby said.

He urges everyone to fill out the census.

鈥淲hen we release this data in 2022, they鈥檙e going to provide a very rich portrait of who we are as Canadians,鈥 he said. 鈥淚t鈥檚 going to provide new insight as to how badly the pandemic affected us, the social perspective as well as economic perspective.鈥