In most cases, a foreign national needs a work permit in order to legally work in Canada. To obtain a work permit, it is usually required to get a job offer letter from the employer and to apply for an approval of ESDC（Employment and Social Development Canada）.
Work Permit application process
Your employer will apply for LMIA (Labour Market Impact Assessment). ESDC will examine the job offer in light of the company’s size, the number of employees, as well as applicant’s prospective labour conditions. (position, wages, etc.)
ESDC will issue positive/negative LMIA according to the criteria.
The applicant will submit the positive LMIA along with all required documents to apply for a work permit.