Help, how to write the invitation letter for visiting relatives in Canada? What do you need?

It is probably about who invited who (relationship) to visit Canada, how long it will take to visit Canada by the way, who will pay the bill, where is the home address of the inviter, and so on. When submitting information, you also need to provide work flow, visa page or maple leaf card, which can prove that the inviter is living a normal life in Canada and has the ability to receive relatives.