The skilled worker is subject to a point system. To be eligible for permanent residence status the immigrant must receive a total of at least 70 points. Points are awarded in the following categories such as; age, education, language ability, occupation, occupational demand, years of experience, family in Canada and personal suitability. The government of Canada publishes a list of specific occupations which they have graded and have determined are occupations which are "in demand" in Canada. In order to apply you must be described in one of these occupations. These occupations also have specific educational and experience requirements which is described in the National Occupations Classification Manual System.
All foreign workers must satisfy that they are not taking a job away from a Canadian before they are issued a temporary work permit. Getting proper permission from the Canadian government that the Canadian labour market is not effected can be a complex and tedious task. It is mainly determined by which occupations are in demand in Canada. The Canadian Immigration Act also addresses certain situation which are exempt from this requirement. The exemptions are often very case specific and again can be a rather complex area of Immigration law. It is best to address each situation individually before rendering an opinion whether an exemption exists or not.