In most cases, you need a work permit to work in Canada. Usually, you have to submit your work permit application from outside Canada. In some situations, you can apply from inside Canada or at the border as you enter Canada. 

A work permit does not allow to you live in Canada permanently. To obtain your status, you must be qualified under one of the immigration categories as a permanent resident.

Generally, there are two types of work permits: employer-specific work permits and open work permits.

An employer-specific work permit allows you to work according to the conditions on your work permit, indicating the employer’s name you can work for, how long you can work, and the location where you can work (if applicable). You can get the employer-specific work permit as a result of positive Labour Market Impact Assessment (LMIA), issued by the government of Canada. A positive LMIA confirms that there are no Canadian citizens or permanent residents readily available to fill the existing job position and therefore authorizes the hiring of foreign workers. Usually, the employers need to get the LMIA to hire you.

An open work permit is not a job specific permit in some cases which means that there is no need to obtain the LMIA and there is no need to mention the job offer. You may be qualified for an open work permit if you are: (a) an international Post-Graduate student (work permit up to 3 years); (b) a spouse/common-law of a skilled worker or international student; (c) awaiting your permanent residence in Canada, or being a member of Family Class of such applicant; (d) a refugee/claimant, protected person and/or their family member; (e ) a young worker participating in International Experience Class program.

There are some situations when the work permit is not required, subject to additional eligibility criteria.