Visitors are persons who are not permanent residents or Canadian citizens, and meet the requirements to enter Canada for a temporary stay as a visitor. Citizens of Visa countries need to acquire a Temporary Resident Visa before coming to Canada and the vast majority of citizens of non-visa countries, require an eTA (electronic Travel Authorization). Visitors are restricted in length of stay, they cannot work without authorization, and can only go to school for a maximum of six months. The normal period of stay is six months but that can be changed by an officer at the port of entry by using a Visitor Record. It can also be extended from within Canada, in certain circumstances. The final decision on entry to Canada is made at the port-of-entry by the CBSA officer, upon arriving in Canada, or by a visa officer when you try to renew your visa from within Canada.