A visa is a travel document that is used to enter the country, whereas a Canadian work permit allows foreign citizens to work there.A visa, also known as a temporary residence visa (TRV), is a real sticker that is affixed to your passport and serves as a means of travel pass that enables foreign citizens to enter Canada or transit through a Canadian airport.Note: Even if you have a valid work permit, you cannot re-enter Canada without a valid visa or eTA.