VISAS
It can is divided into two categories:
1- Temporary resident = tourism, study or work
2- Permanent resident = immigrant
PERMANENCE
The visa is taken on Brazilian soil and has a certain validity but it does not necessarily mean that you can stay on Canadian soil all that time.
So only when you travel, the Canadian official will determine the length of stay for that period, and will stamp the validity on your passport.
Usually for a student visa the length of stay is the same as the visa, so it's easy to get confused!
PERMISSION
A permit is a letter issued with the visa which specifies what activities you can or cannot do, such as a study permit or a work permit.
That is, you can have a student visa and work permit.
Each document has its validity, sometimes with the same date but they are distinct.
Whenever you apply for a visa, there is a possibility of having a positive or negative answer.
The probability of acceptance is very high if you meet Canadian standards such as proving that you can support yourself during the period you will be studying.
If the visa is denied, the school will refund the amount paid in part, under the signed contract, generally the application fee and administrative fee are withheld.