Such entries must occur within the time allowed for your stay in Canada. A multiple entry visa allows you to enter Canada from any country as often as you wish during the validity of the visa, maximum five years. A transit visa is required for travel through Canada to another country by those persons who need a visitor visa and whose flight or bus will stop in Canada for less than 48 hours. To obtain a transit visa you must provide specific evidence of your travel arrangements from your transportation company or travel agent. American visa regulations are different from Canadian visa regulations in this respect.
Travellers are responsible for obtaining the appropriate American visa for their needs.
You must satisfy the visa officer that you meet the requirements of the Canadian Immigration Act and Regulations and that you will be in Canada for a temporary stay. Citizens and residents of certain countries require additional formalities which could add two or more weeks to the normal processing period. The visa office will advise you further if such requirements apply to you. Your spouse and children who wish to visit Canada must apply for permission to do so. As long as you all apply together it will not be necessary for each person to fill out separate forms.