An RRSP is a registered account that allows you to make tax-deferred contributions towards your retirement savings plan. Subject to certain limits, each dollar you contribute to the plan lowers your taxable income by the amount you invest. Once you have made a contribution to an RRSP, your investments can grow tax-free until withdrawn.
The goal is to defer your tax payments on the money you contribute until you’ve retired, at which point you will most likely be in a lower tax bracket.