There are several types of accounts that can be used for your investments.  There is a time and place for each of these accounts and there is definitely overlap in some areas too.  Information about account types can easily be found elsewhere so I've kept my descriptions focused to the main points and provided links to more detailed information (as a start).  After reading just this page you'll be armed with enough Google search phrases to keep you going if you need it.

In an RRSP (sometimes called just RSP), for any money that you place into the account, you get a tax deduction. Unfortunately, there are limits on how much you can contribute every year. Once your money is in the account, if it grows it will be sheltered from income tax (what happens in the account, stays in the account).  As a result your money can grow much faster than if the money was in a non-registered account. When you withdraw, the money will be taxed as if it is income, but hey - it's been growing for 30 or 40 or 50 years tax free so try not to complain too much! 

RRSP and related plans - Canada Revenue Agency

Frequently Asked Questions: RSPs - TD Canada Trust

A Spousal RRSP (sometimes called a SRSP) is a special type of RRSP.  In a Spousal RRSP one spouse opens the account (Spouse A) and the other spouse contributes to it (Spouse B). When the money is withdrawn, it is taxed in the hands of the spouse who opened the account (Spouse A).  Couples use it to spread the investments between themselves so that at retirement, both spouses can aim to draw the least amount of tax overall.  Note that there are rules that govern how long the money must reside within the account before it deemed property of the other spouse.

Spousal RRSPs: Timing matters - MoneySense

How does a spousal RRSP work - Gena Katz - Morningstar