“Aboriginal Peoples” is a collective name for all of the original peoples of Canada and their descendants. Section 35 of the Constitution Act of 1982 specifies that the Aboriginal Peoples in Canada consist of three groups – Indian (First Nations), Inuit and Métis. It should not be used to describe only one or two of the groups.
Aboriginal people – When referring to Aboriginal people with a lower case people, you are simply referring to more than one Aboriginal person rather than the collective group of Aboriginal Peoples.
Non-Aboriginal people (not peoples) – This term refers to anyone who is not an Aboriginal person. Note that the non stays lowercase.
Aboriginal nations – The Royal Commission on Aboriginal Peoples (RCAP) used this term in its final report. RCAP defines Aboriginal nations as “a sizeable body of Aboriginal people with a shared sense of national identity that constitutes the predominant population in a certain territory or collection of territories.””