Federal laws oblige you to convert your RRSP (which allowed you to grow your retirement nest egg tax free),  to a RRIF(Registered Retirement Income Fund) no later than December 31st in the year you turn 71 years of age.  Note that you can convert an RRSP to a RRIF before you turn 71 if you choose to. 
 
A RRIF is similiar to an RRSP in the sense that you may choose to keep the same investments within the plan, which continue to grow tax free.
 
The only difference is that with a RRIF you are obliged to withdraw a certain minimum amount every calendar year.  The minimum amount varies from year to year and is based on your age.

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