Condo insurance protects the units within a condo building. You would get it to protect your contents such as appliances, clothing, and furniture (and would also cover items stored in a locker). 

It would also provide additional living expenses in the event of an insured loss (if you had to temporarily move out) as well as the condo owner's liability for any bodily injury or property damage that was unintentionally caused by others in the building.

No, condo, home, or tenant insurance is not mandatory in Canada, although the condo association, or the owner of the condo, may require you to have to move in. You also need insurance to secure a mortgage to purchase a home or condo. So, even though it is not legally required to have, there are other outlets that may require the homeowner to purchase it.

If you own a condo or rent a house or apartment, some landlords may require tenants to have tenant insurance before moving in and condo corporations and lenders may require condo unit owners to show proof of insurance before moving in as well.

You will need to get strata insurance in BC (also known as condo insurance).
All strata corporations in B.C. are required by the Strata Property Act to carry insurance. So you will need to have it before moving in, or before purchasing the unit.

Major perils, such as fire, wind, water, and lightning, must be covered under the strata insurance policy. A typical strata insurance policy covers damage to the common property such as the hallways and party rooms of the building.

In British Columbia and some parts of Alberta, condominiums are also known as strata. The definition of what is owned by the unit owner depends on the condominium or strata declaration. As the unit owner,  you have title to your unit as well as a share in the common property of the condominium. The common areas of buildings include places such as the lobby, rooftop patio, swimming pool, parking garage, and other amenities. 

A 'bare land' strata or condominium may have only a few common areas (not many amenities) such as streets or roadways that provide access to the units. These are usually common with older condominium buildings.

In British Columbia and some parts of Alberta, strata housing is often referred to as condos or condominiums. However, strata housing not only includes apartment-style condominiums but can also include: duplexes, townhouses, fractional vacation properties, and even single-family homes in bare land strata corporations (“strata subdivisions”).

Condo building insurance is different. This is purchased by the condo corporation to cover damage to the building and the common areas and liability on the property. This is usually included in the monthly condo maintenance fees.