Parliamentary Committees examine specific issues at a level of detail that is not possible in the House of Commons or the Senate. There are permanent (aka standing) committees and legislative or special committees created as needed to assess specific bills, issues, proposals, or actions.
Royal commissions, or commissions of inquiry, are appointed by Cabinet under the terms of the Inquiries Act in order to carry out full and impartial investigations of specific national problems. The terms of reference for the commission and the powers and the names of the commissioners are officially stated by an Order-in-Council. When the investigation is complete, the findings of the commission are reported to Cabinet and the Prime Minister for appropriate action.
National Inquiry into Missing and Murdered Indigenous Women and Girls