The RRSP, also known as the Registered Retirement Savings Plan, is the primary retirement savings account for Canadians. The main benefit of the RRSP is the ability to defer income tax and grown investments tax free as a way of saving for retirement. In other words, money you put in today is not taxed, it grows tax free, and you only have to pay that tax when you withdraw.
Just like the TFSA, an RRSP is not an investment. It is rather, a type of account that can be used to hold different types of investments. It is not uncommon for people to believe that the RRSP itself is an investment, as they are unaware of what they are invested in within the RRSP. You can hold a variety of different investments inside an RRSP.