Most citizens of Europe and Australia, and some American and Asian countries can come to Canada for shorter periods of time without needing to obtain a visa prior to entry. If you are a citizen of a country that Canada has stricter requirements for, you will need a temporary resident visa (TRV).
You can find out whether you require a visa to enter Canada, here(https://www.cic.gc.ca/english/visit/visas.asp)
With this type of visitor’s visa, you can also enroll in any short-term educational programs (i.e with a duration of less than 6 months).
If you are planning to stay for more than 6 months in Canada, you will need to apply for a super visa.
Depending on how long your passport is valid for, a super visa can be issued for a period of up to 10 years, allowing you to stay for several periods of up to 2 years each within that 10-year period.
If you have a job offer from a Canadian employer, or if your skills are in high demand in the Canadian job market, you can apply for a work permit. The application is evaluated based on criteria such as the credibility of the job offer, whether it is hard to find someone who is already inside Canada who can do this job, whether your credentials are recognized in Canada, and whether the Canadian government indeed deems the skills “in high demand”.
If you have a letter of admission from a qualified Canadian institution and are planning to study in Canada for a period of more than 6 months, you will need to apply for a study permit. Please keep in mind that even with a study permit, you would still need to have a temporary resident visa in order to enter Canada