An open work permit is one that enables a foreign worker to work for any employer in Canada. Open work permits do not require foreign nationals to obtain a Labour Market Impact Assessment or a job offer when applying to Immigration, Refugees and Citizenship Canada for a work permit.
Closed work permits require a foreign worker to only work for the employer who has obtained a positive LMIA and provided them with a job offer. If a foreign worker is no longer going to work for this employer, they need to apply to change the conditions of their work permit if they wish to continue to legally work in Canada.