A visitor visa is an official document that is placed in your passport by a Canadian visa office that allows persons who are not Canadian citizens or permanent residents of Canada to enter or re-enter Canada.
It shows that you have met the requirements of the Immigration and Refugee Protection Act (IRPA) and the Immigration and Refugee Protection Regulations for admission to Canada as a temporary resident (either as a visitor, a student, or a worker).Visitors are restricted in length of stay and subject to various conditions.You must meet some basic requirements to get a visitor visa.
Valid travel document
No criminal or immigration-related convictions.
Convince an immigration officer that you will leave Canada at the end of your visit.