It is at this moment that it is important to ask the right questions, "Is such a primary datum really part of the image, of such an object ?" Or in other words, does this data field belong to that particular file ?
You will see that the answer is not as obvious as it seems, let's take the example of the country, and ask the question, is that the country name, is a part of the image of the object Customer ?
The answer is necessarily NO, The name of a country is not a part of the image of the real world object COUNTRY ! You follow me ?

In fact there is a catalog (a set) of the countries of the world, consequently we could consider that the data field COUNTRY  (which is a part of the image that one wishes on a client) could be a criterion of application in a catalog of countries of the world.
It is then up to us to decide whether or not it is interesting to create other sets in our system. I would not teach you the advantages of creating such a catalog (modification Of data at one place and one only, obtaining statistical results greatly facilitated, etc ...). Let us take the case of product categories, the decision to create this catalog may have been taken simply for obtaining statistical data or because, in each category, we wanted to associate data such as a particular taxes rate per category, or Adequate transport costs, etc ...