Work visas allow you to come to Canada and be legally allowed to work for a short period of time. This visa can help you get points to qualify for a federal skilled worker program. The period granted is usually 1-2 years and you can apply for an extension if necessary.
There are two types:
Open: An open visa does not require a job offer prior to arriving. You are able to apply
Restricted: A restrictive visa allows you to work for the company that offered it to you. This requires a job offer prior to arriving.