Regular TRV is for everyone, SV is only for parents/grandparents of a Canadian citizen or PR.
Another difference is regular TRV doesn't require medical insurance/test, SV requires it.
In my case, I applied for my mom's regular TRV first and got denied so fast lol because of no strong ties to home country, financial & travel history. So I applied for SV, costly because of medical insurance/test, but, she is unemployed, all her children are in Canada, no recent travel abroad, approved, she is here with me since December 10th.
@adelosreyes you parent might get denied because of travel history, but it's your choice if you want to apply TRV first.