RRSPs are designed to encourage you to save for retirement. TFSAs, on the other hand, are designed to help you save for anything you want (including retirement).
What about taxes? With an RRSP, you get tax deductions or refunds when you contribute or file your return. TFSA contributions aren't tax-deductible, but you don't pay tax on any money you take out (unlike RRSP withdrawals, which are taxed).
Check out our
TFSA vs. RRSP table for an overview of the main differences between the plans.