To say what colinear is, you first have to say what linear is, in this case a line. You cannot define colinear by line and line by colinear at the same time. In this case they would be equivalent and the answer would be trivially yes. So in order to get some meaning to the question, you have to put some truth in it somewhere. That's why I asked, what a line is to you. How can I answer a question about colinear points, if it isn't clear what a line is?
Two points define a straight line. So the original question is trivially answered by yes. Usually when asking about collinear, the question involves more than two points.
