The value of goods and services constitute the basic of the science of the economy as much as the motivation of the economic agents.
In this course, we are really at the basic of the science of the economy. We should also establish the basic elements of its method and the main tolls used by the economists.
When we are at the basic, the deep bottom of a science, our words need to remain simple. Things will get more complicated later, fast enough in the science of the economy. We have already seen it in the first course with the name itself of that science.
Furthermore, I like this Robert Kiyosaki's Rich Dad saying about the words that we use daily, being the most influential for our future. Many writers had said the same thing. It is very important to know very well the basic notions of the science of the economy. Along the course, I will have some special notes and specifications about the words that we use daily as economists, as for the "economic analysis<" in the first course.