Individuals who are not Canadian citizens or permanent residents may require a Temporary Resident Visa (TRV or “visitor visa”) to enter or transit through Canada.  A visitor visa allows individuals to enter and remain in Canada for a restricted period of time. Visitors are prohibited from working or studying without authorization.

To determine if you require a TRV: http://www.cic.gc.ca/english/visit/visas.asp

Starting March 15, 2016, visa-exempt individuals who travel to or transit through Canada by air will need an Electronic Travel Authorization (eTA). To determine if you require an eTA: http://www.cic.gc.ca/english/visit/visas.asp