Canadian visitor visas (Temporary Resident Visa, or TRV) are discretionary — the visa officer has wide latitude to refuse if they're not satisfied you'll leave Canada at the end of your authorized stay. The application is short, but every document needs to support one core message: "I have strong reasons to return home and the means to support myself during my visit."
Refusal rates vary by country, but globally hover around 40%. A well-prepared application can reduce that risk significantly.