Almost all foreign workers require a work permit to be employed in Canada.
Before an application for a work permit should be made the following steps should be taken:
1) an employer must offer the foreign national a job.
2) HRSDC will provide a labour market opinion and confirm the validity of the work permit. If HRSDC believe the job can be filled by a Canadian then the work permit will not be granted.
3) If HRSDC grants permission to the employer to hire a foreign worker the worker should apply to CIC for the work permit.
Work permits are not a form of immigration and are granted for a specific period of time. Although this can be renewed it is not permanent resident status.
Work permits are granted for a specific job. If the employee released from employment then they must either leave Canada or make a request to change their status to visitor. The foreign worker will not be permitted to find another job in Canada without going through the work permit application process again.
Work Permits are for temporary employment of foreign national. If you want to work in Canada on a permanent basis you need to immigrate as a Skilled Worker.