Canada selects skilled immigrants based on their ability to establish themselves economically in Canada and actively participate in the Economy. There are three separate programs which falls under the jurisdiction of the Federal Government i.e. Federal Skilled Worker Program, Fereral Skilled Trades Program, and the Canadian Experience Class.
In January 2015, the Canadian Government launched a new Application Intake Management System called Express Entry to manage how applicants with skilled work experience apply to immigrate to Canada. The above noted programs along with some Provincial Nominee Programs are now managed under the Express Entry System:
(Note: The Province of Quebec does not use Express Entry. It has its own Skilled Worker program and people who intend to live in Quebec must apply to the Province following its own criteria. They may not be eligible to apply to the Federal Government under any of these Skilled Worker Program categories)