Canadian citizens and permanent residents have the full right to enter or leave Canada freely. However, all visitors intending to come to Canada, such as tourists, students and temporary workers, must obtain a Temporary Resident Visa issued by Citizenship and Immigration Canada before they can enter Canada. There are several categories under which an applicant can apply for temporary resident status: (student visa, temporary worker visa and tourist visa)
The fact of being ready to work and having a job offer in Canada is not enough to trigger the process of studying the application for a work permit. The prospective employer must first demonstrate to the Department of Services Canada (formerly Human Resources Development Canada) that they have made serious efforts to hire a Canadian or permanent resident to fill the job offered and that despite reasonable efforts to do so, they have been unable to find one. If Service Canada approves the shortage, a positive opinion on the job offer will be forwarded to Immigration Services.
Once the job offer has been validated, an application for a work permit, then can be submitted to a federal immigration office abroad which, after studying the file, will often interview the candidate before verifying his diplomas, work experience in the job offered and eventually issuing the employment authorization.