Thank you for your question.
CRA stands for the Canada Revenue Agency.
Canada Revenue Agency is the revenue service of the Canadian federal government and most provincial and territorial governments. The CRA collects taxes, administers tax law and policy, and delivers benefit programs and tax credits.
A social Insurance Number (SIN) is a 9-digit number that you require to work in Canada or access government programs and benefits.
For more information click on the hyperlinks - CRA and SIN.
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