Visa-exempt foreign nationals need an EVA to enter or transit Canada by air only.. These travellers do not need an EV when they arrive in the country by car, bus, train or boat (including cruise ships). Beware of websites that claim otherwise in order to sell you a useless document.
Please note that a return trip to Canada-Usa-Canada does not reset your "180-day counter" authorised with the AVE. The 180 days are reset when you pass through the airport only.
Other nationalities will require a visitor's visa (or any other visa appropriate to the purpose of their stay).
An agency service 