Step-by-step explanation:
Ok, imagine I have a finger pointed up, and you have your's as well. They are not congruent / parallell to each other because they are not in the same plane.
Plane: A plane is kind of the space around you, so take a paper and draw a line, the space around the line is called a plane. To make two lines parallell, they have to be straight and be in the same plane
Congruence/congruent= Equal(led) to
Postulates means that you know it without proof, for example, a right angle is 90 degrees.
There are different congruence postulates. It can be used for triangles or for other shapes.
I hope this answers your question, I am not to sure on what you said !